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1.
《Bioscience, biotechnology, and biochemistry》2013,77(10):2348-2351
Bacillus sp. PS3 produces a glycosylated flagellin. In this study, a number of the glycosylated residues of the flagellin protein were found to be located in the central variable region of this protein. We also report that the motility defect of the Bacillus subtilis flagellin mutant was complemented by Bacillus sp. PS3 flagellin variants without glycosylation, which contained amino acid substitutions and intragenic duplications in the variable region of flagellin. 相似文献
2.
《Bioscience, biotechnology, and biochemistry》2013,77(2):410-413
A previous report described the presence of a self-splicing group I intron in a flagellin gene from a thermophilic Bacillus species. Here, we present evidence that the splicing reaction of the flagellin introns is dependent on temperature. Furthermore, a complementation analysis using a Bacillus subtilis flagellin-deficient mutant indicated that the intron-containing flagellin gene significantly restored the motility of the mutant at higher temperatures. 相似文献
3.
《Bioscience, biotechnology, and biochemistry》2013,77(12):2758-2761
A group I intron that can be spliced in vivo and in vitro was identified in the flagellin gene of the thermophilic bacterium Geobacillus stearothermophilus. We also found one or two intervening sequences (IVS) of flagellin genes in five additional bacterial species. Furthermore, we report the presence of these sequences in two sites of a highly conserved region in the flagellin gene. 相似文献
4.
Anna Hanuszkiewicz Paula Pittock Fiachra Humphries Hermann Moll Amanda Roa Rosales Antonio Molinaro Paul N. Moynagh Gilles A. Lajoie Miguel A. Valvano 《The Journal of biological chemistry》2014,289(27):19231-19244
Burkholderia cenocepacia is an opportunistic pathogen threatening patients with cystic fibrosis. Flagella are required for biofilm formation, as well as adhesion to and invasion of epithelial cells. Recognition of flagellin via the Toll-like receptor 5 (TLR5) contributes to exacerbate B. cenocepacia-induced lung epithelial inflammatory responses. In this study, we report that B. cenocepacia flagellin is glycosylated on at least 10 different sites with a single sugar, 4,6-dideoxy-4-(3-hydroxybutanoylamino)-d-glucose. We have identified key genes that are required for flagellin glycosylation, including a predicted glycosyltransferase gene that is linked to the flagellin biosynthesis cluster and a putative acetyltransferase gene located within the O-antigen lipopolysaccharide cluster. Another O-antigen cluster gene, rmlB, which is required for flagellin glycan and O-antigen biosynthesis, was essential for bacterial viability, uncovering a novel target against Burkholderia infections. Using glycosylated and nonglycosylated purified flagellin and a cell reporter system to assess TLR5-mediated responses, we also show that the presence of glycan in flagellin significantly impairs the inflammatory response of epithelial cells. We therefore suggest that flagellin glycosylation reduces recognition of flagellin by host TLR5, providing an evasive strategy to infecting bacteria. 相似文献
5.
The cytoplasmic level of flagellin (called Hag) is homeostatically regulated in the Gram-positive bacterium Bacillus subtilis by a partner-switching mechanism between the protein FliW and either the Hag structural protein or CsrA, an RNA binding protein that represses hag translation. Here we show that FliW and the putative secretion chaperone FliS bind to Hag simultaneously but control Hag translation by different mechanisms. While FliW directly inhibits CsrA activity, FliS antagonizes CsrA indirectly by binding to Hag, enhancing Hag secretion, and depleting Hag in the cytoplasm to trigger the FliW partner switch. Consistent with a role for FliS in potentiating Hag secretion, the mutation of fliS crippled both motility and flagellar filament assembly, and both phenotypes could be partially rescued by artificially increasing the concentration of the Hag substrate through the absence of CsrA. Furthermore, the absence of FliS resulted in an approximately 30-fold reduction in extracellular Hag accumulation in cells mutated for CsrA (to relieve homeostatic control) and the filament cap protein FliD (to secrete flagellin into the supernatant). Thus, we mechanistically discriminate between the FliW regulator and the FliS chaperone to show that secretion disrupts flagellin homeostasis and promotes high-level flagellin synthesis during the period of filament assembly in B. subtilis. 相似文献
6.
A ten gene‐containing genomic island determines flagellin glycosylation: implication for its regulatory role in motility and virulence of Xanthomonas oryzae pv. oryzae
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Chao Yu Huamin Chen Fang Tian Fenghuan Yang Xiaochen Yuan Ching‐Hong Yang Chenyang He 《Molecular Plant Pathology》2018,19(3):579-592
7.
8.
Jennifer L. Parker Rebecca C. Lowry Narciso A. S. Couto Phillip C. Wright Graham P. Stafford Jonathan G. Shaw 《Molecular microbiology》2014,92(2):258-272
Bacterial swimming is mediated by rotation of a filament that is assembled via polymerization of flagellin monomers after secretion via a dedicated flagellar Type III secretion system. Several bacteria decorate their flagellin with sialic acid related sugars that is essential for motility. Aeromonas caviae is a model organism for this process as it contains a genetically simple glycosylation system and decorates its flagellin with pseudaminic acid (Pse). The link between flagellin glycosylation and export has yet to be fully determined. We examined the role of glycosylation in the export and assembly process in a strain lacking Maf1, a protein involved in the transfer of Pse onto flagellin at the later stages of the glycosylation pathway. Immunoblotting, established that glycosylation is not required for flagellin export but is essential for filament assembly since non‐glycosylated flagellin is still secreted. Maf1 interacts directly with its flagellin substrate in vivo, even in the absence of pseudaminic acid. Flagellin glycosylation in a flagellin chaperone mutant (flaJ) indicated that glycosylation occurs in the cytoplasm before chaperone binding and protein secretion. Preferential chaperone binding to glycosylated flagellin revealed its crucial role, indicating that this system has evolved to favour secretion of the polymerization competent glycosylated form. 相似文献
9.
Cheryl P. Ewing Ekaterina Andreishcheva Patricia Guerry 《Journal of bacteriology》2009,191(22):7086-7093
The major flagellin of Campylobacter jejuni strain 81-176, FlaA, has been shown to be glycosylated at 19 serine or threonine sites, and this glycosylation is required for flagellar filament formation. Some enzymatic components of the glycosylation machinery of C. jejuni 81-176 are localized to the poles of the cell in an FlhF-independent manner. Flagellin glycosylation could be detected in flagellar mutants at multiple levels of the regulatory hierarchy, indicating that glycosylation occurs independently of the flagellar regulon. Mutants were constructed in which each of the 19 serine or threonines that are glycosylated in FlaA was converted to an alanine. Eleven of the 19 mutants displayed no observable phenotype, but the remaining 8 mutants had two distinct phenotypes. Five mutants (mutations S417A, S436A, S440A, S457A, and T481A) were fully motile but defective in autoagglutination (AAG). Three other mutants (mutations S425A, S454A, and S460A) were reduced in motility and synthesized truncated flagellar filaments. The data implicate certain glycans in mediating filament-filament interactions resulting in AAG and other glycans appear to be critical for structural subunit-subunit interactions within the filament.Flagellins from many polarly flagellated bacteria are glycosylated (reviewed in reference 22). The best-characterized examples are the flagellins from Campylobacter spp. that are decorated with as many as 19 O-linked glycans that can contribute ∼10% to the weight of flagellin (38). The genes encoding the enzymes for biosynthesis of the glycans found on Campylobacter flagellins and the respective glycosyltransferases are located adjacent to the flagellin structural genes in one of the more hypervariable regions of the Campylobacter genome (3, 16, 28, 37). Most strains appear to carry the genes for synthesis of two distinct nine-carbon sugars that decorate flagellin: pseudaminic acid (PseAc) and an acetamidino form of legionaminic acid (LegAm) (23). In contrast, Campylobacter jejuni strain 81-176 contains only the pathway for synthesis of PseAc (9) and derivatives of PseAc that include an acetylated form (PseAcOAc), an acetamidino form (PseAm), and a form of PseAm with a glutamic acid moiety attached (PseAmOGln) (25, 34, 38). The flagellins of C. jejuni strain NCTC 11168 have recently been shown to be glycosylated with PseAc and LegAm, as well as two novel derivatives of PseAc, a di-O-methylglyceric acid and a related acetamidino form (24). Thus, although all of the flagellar glycans appear to be based on either PseAc and/or LegAm, there are variations among strains that contribute to serospecificity and reflect the heterogeneity of the flagellin glycosylation loci (23, 24).The function of the glycosyl modifications to flagellar structure and to the biology of campylobacters is not fully understood. Although most polarly flagellated bacteria appear to glycosylate flagellin, mutation of the genes involved in glycosylation does not generally result in loss of motility (22). However, flagella from C. jejuni, Campylobacter coli, and Helicobacter pylori, all members of the epsilon division of Proteobacteria, are unable to assemble a filament in the absence of a functional glycosylation system (7, 33). Also, changes in the glycans on campylobacter flagellins have been shown to affect autoagglutination (AAG) and microcolony formation on intestinal epithelial cells in vitro (5, 9). Thus, a mutant of C. jejuni 81-176 that was unable to synthesize PseAm assembled a flagellar filament, but the sites on the flagellin subunits that were normally glycosylated with PseAm were instead glycosylated with PseAc. This mutant was reduced in AAG, adherence, and invasion of INT407 cells and was also attenuated in a ferret diarrheal disease model (9). C. coli VC167 has both PseAc and LegAm pathways. Mutants that were defective in either pathway could still assemble flagellar filaments composed of subunits that were modified with the alternate sugar, but these mutants showed defects in AAG (7). A VC167 double mutant, defective in both PseAc and LegAm synthesis, was nonflagellated (7). Collectively, these data suggest that some glycosylation is required for either secretion of flagellin or for interactions between subunits within the filament.Flagellar biogenesis in C. jejuni is a complex process that is highly controlled by the alternate sigma factors σ28 and σ54, a two-component regulatory system composed of the sensor kinase FlgS and the σ54-response regulator FlgR, and the flagellar export apparatus (15, 39). Both flgR and flgS genes undergo slip strand mismatch repair in C. jejuni strain 81-176, resulting in an on/off-phase variation of flagellar expression (13, 14). The major flagellin gene, flaA, and some other late flagellar genes are regulated by σ28; the genes encoding the minor flagellin, flaB, and the hook and rod structures are regulated by σ54. Here, we examine several aspects of glycosylation to flagellar function in C. jejuni 81-176. We demonstrate that some components of the flagellar glycosylation machinery are localized to the poles of the cell, but independently of the signal recognition particle-like flagellar protein, FlhF, and that flagellin glycosylation occurs independently of the flagellar regulon. We also show that the glycans on some amino acids appear to play a structural role in subunit interactions in the filament, while others affect interactions with adjacent filaments that result in AAG. 相似文献
10.
Kenji Kimura Akira Tsukamoto Yasumasa Ishii Toshiya Takano Kunio Yamane 《Applied microbiology and biotechnology》1988,27(4):372-377
Summary The gene for maltohexaose producing amylase from an alkalophilic bacterium, Bacillus sp. # 707, was cloned in an Escherichia coli phage D69 and recloned in an E. coli plasmid pBR322 and a Bacillus subtilis plasmid pUB110, designated the resulting plasmids as pTUE306 and pTUB812, respectively. A common DNA region of approximately 2.5 kb was defined among the inserted DNAs. The enzymatic activity was lost when a part of the common region was deleted. The plasmids were stably maintained and the gene was well expressed in the bacterium, B. subtilis[pTUB812] which produced more than 70 times higher activity in the culture medium than did Bacillus sp. # 707. The major product of hydrolysis of starch by the enzymes of B. subtilis[pTUB812] and E. coli[pTUE306] was maltohexaose. The cloned gene corresponded to one of the genes for five components of malto-oligosaccharide-producing amylases of Bacillus sp. # 707.Abbreviations G1, G2, G3, G4, G5, and G6
glucose, maltose, maltotriose, maltotetraose, maltopentaose, and maltohexaose, respectively
- kb
kilobase pairs
- kdal
kilodalton
- []
designated plasmid-carrier state 相似文献
11.
Cloning and Comparison of fliC Genes and Identification of Glycosylation in the Flagellin of Pseudomonas aeruginosa a-Type Strains 总被引:2,自引:0,他引:2
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Pseudomonas aeruginosa a-type strains produce flagellin proteins which vary in molecular weight between strains. To compare the properties of a-type flagellins, the flagellin genes of several Pseudomonas aeruginosa a-type strains, as determined by interaction with specific anti-a monoclonal antibody, were cloned and sequenced. PCR amplification of the a-type flagellin gene fragments from five strains each yielded a 1.02-kb product, indicating that the gene size is not likely to be responsible for the observed molecular weight differences among the a-type strains. The flagellin amino acid sequences of several a-type strains (170018, 5933, 5939, and PAK) were compared, and that of 170018 was compared with that of PAO1, a b-type strain. The former comparisons revealed that a-type strains are similar in amino acid sequence, while the latter comparison revealed differences between 170018 and PAO1. Posttranslational modification was explored for its contribution to the observed differences in molecular weight among the a-type strains. A biotin-hydrazide glycosylation assay was performed on the flagellins of three a-type strains (170018, 5933, and 5939) and one b-type strain (M2), revealing a positive glycosylation reaction for strains 5933 and 5939 and a negative reaction for 170018 and M2. Deglycosylation of the flagellin proteins with trifluoromethanesulfonic acid (TFMS) confirmed the glycosylation results. A molecular weight shift was observed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis for the TFMS-treated flagellins of 5933 and 5939. These results indicate that the molecular weight discrepancies observed for the a-type flagellins can be attributed, at least in part, to glycosylation of the protein. Anti-a flagellin monoclonal antibody reacted with the TFMS-treated flagellins, suggesting that the glycosyl groups are not a necessary component of the epitope for the human anti-a monoclonal antibody. Comparisons between a-type sequences and a b-type sequence (PAO1) will aid in delineation of the epitope for this monoclonal antibody. 相似文献
12.
Takami H Nakasone K Ogasawara N Hirama C Nakamura Y Masui N Fuji F Takaki Y Inoue A Horikoshi K 《Extremophiles : life under extreme conditions》1999,3(1):29-34
The nucleotide sequences of three independent fragments (designated no. 3, 4, and 9; each 15–20 kb in size) of the genome
of alkaliphilic Bacillus sp. C-125 cloned in a λ phage vector have been determined. Thirteen putative open reading frames (ORFs) were identified in
sequenced fragment no. 3 and 11 ORFs were identified in no. 4. Twenty ORFs were also identified in fragment no. 9. All putative
ORFs were analyzed in comparison with the BSORF database and non-redundant protein databases. The functions of 5 ORFs in fragment
no. 3 and 3 ORFs in fragment no. 4 were suggested by their significant similarities to known proteins in the database. Among
the 20 ORFs in fragment no. 9, the functions of 11 ORFs were similarly suggested. Most of the annotated ORFs in the DNA fragments
of the genome of alkaliphilic Bacillus sp. C-125 were conserved in the Bacillus subtilis genome. The organization of ORFs in the genome of strain C-125 was found to differ from the order of genes in the chromosome
of B. subtilis, although some gene clusters (ydh, yqi, yer, and yts) were conserved as operon units the same as in B. subtilis.
Received: April 17, 1998 / Accepted: June 23, 1998 相似文献
13.
14.
D. P. Bayley V. Florian A. Klein K. F. Jarrell 《Molecular & general genetics : MGG》1998,258(6):639-645
The highly conserved nature of the 5′-termini of all archaeal flagellin genes was exploited by polymerase chain reaction
(PCR) techniques to amplify the sequence of a portion of a flagellin gene family from the archaeon Methanococcus vannielii. Subsequent inverse PCR experiments generated fragments that permitted the sequencing of a total of three flagellin genes,
which, by comparison with flagellin genes that have been sequenced, from other archaea appear to be equivalent to flaB1, flaB2, and flaB3 of M. voltae. Analysis of purified M. vannielii flagellar filaments by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) revealed two major flagellins
(Mr= 30 800 and 28 600), whose N-terminal sequences identified them as the products of the flaB1 and flaB2 genes, respectively. The gene product of flaB3 could not be detected in flagellar filaments by SDS-PAGE. The protein sequence data, coupled with the DNA sequences, demonstrated
that both FlaB1 and FlaB2 flagellins are translated with a 12-amino acid signal peptide which is absent from the mature protein
incorporated into the flagellar filament. These data suggest that archaeal flagellin export differs significantly from that
of bacterial flagellins.
Received: 27 November 1997 / Accepted: 19 March 1998 相似文献
15.
High-level expression of an endoxylanase gene from Bacillus sp. in Bacillus subtilis DB104 for the production of xylobiose from xylan 总被引:1,自引:0,他引:1
K. J. Jeong I. Y. Park M. S. Kim S. C. Kim 《Applied microbiology and biotechnology》1998,50(1):113-118
To produce xylobiose from xylan, high-level expression of an endoxylanase gene from Bacillus sp. was carried out in Bacillus subtilis DB104. A 1.62-kb SmaI DNA fragment, coding for an endoxylanase of Bacillus sp., was ligated into the Escherichia coli/B. subtilis shuttle vector pJH27Δ88, producing pJHKJ4, which was subsequently transformed into B. subtilis DB104. A maximum endoxylanase activity of 105 U/ml was obtained from the supernatant of B. subtilis DB104 harboring pJHKJ4. The endoxylanase was purified to homogeneity by ion-exchange chromatography and the production profile
of xylooligosaccharides from xylan by the endoxylanase was examined by HPLC with a carbohydrate analysis column. Xylobiose
was the major product from xylan at 40 °C and its proportion in the xylan hydrolyzates increased with the reaction time; at
12 h, over 60% of the reaction products was xylobiose. These results suggest that xylobiose, which has a stimulatory effect
on the selective growth of the intestinal bacterium Bifidobacterium, can be mass-produced effectively by the endoxylanase of Bacillus sp. cloned in B. subtilis.
Received: 2 January 1998 / Received revision: 4 March 1998 / Accepted: 4 March 1998 相似文献
16.
New approach for the detection of non-ribosomal peptide synthetase genes in Bacillus strains by polymerase chain reaction 总被引:1,自引:0,他引:1
Arthur Tapi Marlène Chollet-Imbert Bart Scherens Philippe Jacques 《Applied microbiology and biotechnology》2010,85(5):1521-1531
Bacillus strains produce non-ribosomal lipopeptides that can be grouped into three families: surfactins or lichenysins, iturins and
fengycins or plispastatins. These biosurfactants show a broad spectrum of biological activities. To detect strains able to
produce these lipopeptides, a new polymerase chain reaction screening approach was developed using degenerated primers based
on the intraoperon alignment of adenylation and thiolation nucleic acid domains of all enzymes implicated in the biosynthesis
of each lipopeptide family. The comparative bioinformatics analyses of each operon led to the design of four primer pairs
for the three families taking into account the differences between open reading frames of each synthetase gene. Tested on
different Bacillus sp. strains, this technique was used successfully to detect not only the expected genes in the lipopeptide producing strains
but also the presence of a plispastatin gene in Bacillus subtilis ATCC 21332 and a gene showing a high similarity with the polyketide synthase type I gene in the B. subtilis ATCC 6633 genome. It also led to the discovery of the presence of non-ribosomal peptide synthetase genes in Bacillus thuringiensis serovar berliner 1915 and in Bacillus cereus LMG 2098. In addition, this work highlighted the differences between the fengycin and plipastatin operon at DNA level. 相似文献
17.
Swati Chalia Prasad Minakshi Ramanathan Baskar Koushlesh Ranjan 《Geomicrobiology journal》2017,34(9):737-752
In vitro culture experiments using three bacterial strains CSJC1, CSJC2, and CSJC3 isolated from speleothems, Rani cave, Chhattisgarh, India, were studied to examine their biomineralization potential. These speleothems showed high microbial cell enumerations on nutrient agar and iron agar (9 × 104 CFU/g) followed by thiosulfate agar (7 × 104 CFU/g), and 60 diverse strains were isolated. The BLASTn sequence search of 16S rRNA sequences with the NCBI database to establish the identity of CSJC1, CSJC2, and CSJC3 strains yielded similarity scores of ≥99% with the respective organisms, and the strains were identified as CSJC1 – Bacillus sp., CSJC2 – Cupriavidus sp., CSJC3 – Bacillus sp. The phylogenetic analysis of CSJC2 strain suggests that it formed a separate major cluster with Cupriavidus sp. and Cupriavidus necator. The phylogenetic analysis of CSJC1 and CSJC3 strains revealed that it formed a major cluster with several strains of Bacillus sp. and Bacillus subtilis. The biominerals induced by Cupriavidus sp. CSJC2 strain imaged with an ultra high-resolution field emission scanning electron microscope (FE-SEM) were seen as calcified coccoid shells that transformed into calcified dumbbells. FE-SEM imaging of biominerals induced by B. subtilis CSJC1 and CSJC3 tested both on B4 media and sheep blood agar individually showed that the precipitates formed calcified dumbbells that were almost similar but not identical phenotypically, indicating that strain-specific morphologies and crystal formation is easier when Ca is present in the media. This is the first comprehensive report on the possible evidences about the role of Cupriavidus sp. in calcite precipitation isolated from speleothems in the Indian caves. These results allow us to postulate that the identified strains may have a role in the biogenic influences in mineral formations at Rani cave. 相似文献
18.
Kang KD Cho YS Song JH Park YS Lee JY Hwang KY Rhee SK Chung JH Kwon O Seong SI 《Journal of microbiology (Seoul, Korea)》2011,49(3):431-440
1-Deoxynojirimycin (DNJ), a D-glucose analogue with a nitrogen atom substituting for the ring oxygen, is a strong inhibitor
of intestinal α-glucosidase. DNJ has several promising biological activities, including its antidiabetic, antitumor, and antiviral
activities. Nevertheless, only limited amounts of DNJ are available because it can only be extracted from some higher plants,
including the mulberry tree, or purified from the culture broth of several types of soil bacteria, such as Streptomyces sp. and Bacillus sp. In our previous study, a DNJ-producing bacterium, Bacillus subtilis MORI, was isolated from the traditional Korean fermented food Chungkookjang. In the present study, we report the identification
of the DNJ biosynthetic genes in B. subtilis MORI 3K-85 strain, a DNJ-overproducing derivate of the B. subtilis MORI strain generated by γ-irradiation, xhe genomic DNA library of B. subtilis MORI 3K-85 was constructed in Escherichia coli, and clones showing α-glucosidase inhibition activity were selected. After DNA sequencing and a series of subcloning, we
were able to identify a putative Operon which consists of gabT1, yktc1, and gutB1 genes predicted to encode putative transaminase, phosphatase, and oxidoreductase, respectively. When a recombinant plasmid
containing this Operon sequence was transformed into an E. coli strain, the resulting transformant was able to produce DNJ into the culture medium. Our results indicate that the gabT1, yktc1, and gutB1 genes are involved in the DNJ biosynthetic pathway in B. subtilis MORI, suggesting the possibility of employing these genes to establish a large-scale microbial DNJ overproduction system
through genetic engineering and process optimization. 相似文献
19.
Faezi Ghasemi Mohammad Tayeri Alireza 《World journal of microbiology & biotechnology》2007,23(9):1327-1332
Sixteen aerobic endospore-forming Bacillus spp. were isolated from fully fermented tea leaf samples from 10 tea factories in Lahijan and Langrod cities (Gillan province,
Iran). Bacillus spp. isolates were characterized using phenotypic characteristics, antibiotic susceptibility and cellular fatty acid (CFA)
patterns. Based on the data obtained, five isolates of tea Bacillus spp. (TB): TB2, TB4, TB6, TB10 and TB12 belonged to the species B. subtilis. Two isolates, TB1 and TB14 were recognized as B.
licheniformis. Two Bacillus spp. isolates, TB9 and TB 16 were identified as B. sphaericus. Two isolates, TB5 and TB13 were shown to be B. pumilus. Two isolates, TB7 and TB15 belonged to B. cereus. Amongst the isolates, Bacillus sp. TB3, Bacillus sp. TB8 and Bacillus sp. TB11 showed different phenotypic traits, distinct antibiotic sensitivity and fatty acid profiles, and they may represent
novel species. The isolates showed polyphenol oxidase (tyrosinase) and peroxidase activities. The highest polyphenol oxidase
and peroxidase activities were observed for Bacillus sp. TB3 and B. licheniformis TB14, respectively, where values of 5.48 and 3.73 units mL−1 were observed. 相似文献
20.
Sequence Diversity of the Bacillus thuringiensis and B. cereus Sensu Lato Flagellin (H Antigen) Protein: Comparison with H Serotype Diversity
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We set out to analyze the sequence diversity of the Bacillus thuringiensis flagellin (H antigen [Hag]) protein and compare it with H serotype diversity. Some other Bacillus cereus sensu lato species and strains were added for comparison. The internal sequences of the flagellin (hag) alleles from 80 Bacillus thuringiensis strains and 16 strains from the B. cereus sensu lato group were amplified and cloned, and their nucleotide sequences were determined and translated into amino acids. The flagellin allele nucleotide sequences for 10 additional strains were retrieved from GenBank for a total of 106 Bacillus species and strains used in this study. These included 82 B. thuringiensis strains from 67 H serotypes, 5 B. cereus strains, 3 Bacillus anthracis strains, 3 Bacillus mycoides strains, 11 Bacillus weihenstephanensis strains, 1 Bacillus halodurans strain, and 1 Bacillus subtilis strain. The first 111 and the last 66 amino acids were conserved. They were referred to as the C1 and C2 regions, respectively. The central region, however, was highly variable and is referred to as the V region. Two bootstrapped neighbor-joining trees were generated: a first one from the alignment of the translated amino acid sequences of the amplified internal sequences of the hag alleles and a second one from the alignment of the V region amino acid sequences, respectively. Of the eight clusters revealed in the tree inferred from the entire C1-V-C2 region amino acid sequences, seven were present in corresponding clusters in the tree inferred from the V region amino acid sequences. With regard to B. thuringiensis, in most cases, different serovars had different flagellin amino acid sequences, as might have been expected. Surprisingly, however, some different B. thuringiensis serovars shared identical flagellin amino acid sequences. Likewise, serovars from the same H serotypes were most often found clustered together, with exceptions. Indeed, some serovars from the same H serotype carried flagellins with sufficiently different amino acid sequences as to be located on distant clusters. Species-wise, B. halodurans, B. subtilis, and B. anthracis formed specific branches, whereas the other four species, all in the B. cereus sensu lato group, B. mycoides, B. weihenstephanensis, B. cereus, and B. thuringiensis, did not form four specific clusters as might have been expected. Rather, strains from any of these four species were placed side by side with strains from the other species. In the B. cereus sensu lato group, B. anthracis excepted, the distribution of strains was not species specific. 相似文献