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1.
Cuiping Yuan Guoan Zhou Yinghui Li Kejing Wang Zhi Wang Xianghua Li Ruzhen Chang Lijuan Qiu 《Molecular breeding : new strategies in plant improvement》2008,22(4):593-602
Soybean cyst nematode (SCN) (Heterodera glycines Ichinohe) is the most important pathogen in soybean production worldwide and causes substantial yield losses. An apparent
narrow genetic base of SCN resistance was observed in current elite soybean cultivars, and searching for novel SCN resistance
genes as well as novel resistance sources rather than focusing on the two important genes rhg1 and Rhg4 has become another major objective in soybean research. In the present paper we report a 1,477 bp Hs1
pro-1
homolog, named GmHs1
pro-1
. This gene was cloned from soybean variety Wenfeng 7 based on information for Hs1
pro-1
, a beet cyst nematode resistance gene in sugar beet. It has two domains, Hs1pro-1_N and Hs1pro-1_C, both of which are believed
to confer resistance to nematodes. Of the 1,477 bp sequence in GmHs1
pro-1
, an open reading frame of 1,314 bp, encoding a protein with 437 amino acids, was flanked by a 5′-untranslated region of 27 bp
and a 3′-untranslated region of 135 bp. Fourteen single-nucleotide polymorphisms (SNPs) were observed in 44 soybean accessions
including 23 wild soybeans, 8 landraces, and 13 soybean varieties (or lines), among which 5 in wild soybeans and 3 in landrace
accessions were unique. Sequence diversity analysis on the 44 soybean accessions showed π = 0.00168 and θ = 0.00218 for GmHs1
pro-1
; landraces had the highest diversity, followed by wild soybeans, with varieties (or lines) having the lowest. Although we
did not detect a significant effect of selection on GmHs1
pro-1
in the three populations, sequence diversity, unique SNPs, and phylogenetic analysis indicated a slight domestication bottleneck
and an intensive selection bottleneck. High sequence diversity, more unique SNPs, and broader representation across the phylogenetic
tree in wild soybeans and landraces indicated that wild collections and landrace accessions are invaluable germplasm for broadening
the genetic base of elite soybean varieties resistant to SCN.
C. Yuan and G. Zhou contributed to this paper equally. 相似文献
2.
Lee YK Yoon BD Yoon JH Lee SG Song JJ Kim JG Oh HM Kim HS 《Applied microbiology and biotechnology》2007,75(3):567-572
The srfA operon is required for the nonribosomal biosynthesis of the cyclic lipopeptide, surfactin. The srfA operon is composed of the four genes, srfAA, srfAB, srfAC, and srfAD, encoding the surfactin synthetase subunits, plus the sfp gene that encodes phosphopantetheinyl transferase. In the present study, 32 kb of the srfA operon was amplified from Bacillus subtilis C9 using a long and accurate PCR (LA-PCR), and ligated into a pIndigoBAC536 vector. The ligated plasmid was then transformed
into Escherichia coli DH10B. The transformant ET2 showed positive signals to all the probes for each open reading frame (ORF) region of the srfA operon in southern hybridization, and a reduced surface tension in a culture broth. Even though the surface-active compound
extracted from the E. coli transformant exhibited a different R
f value of 0.52 from B. subtilis C9 or authentic surfactin (R
f = 0.63) in a thin layer chromatography (TLC) analysis, the transformant exhibited a much higher surface-tension-reducing
activity than the wild-type strain E. coli DH10B. Thus, it would appear that an intermediate metabolite of surfactin was expressed in the E. coli transformant harboring the srfA operon. 相似文献
3.
Mohsin Abbas Zaidi Gongyin Ye Hongwei Yao Taek H. You Evelin Loit Donald H. Dean Sheikh Riazuddin Illimar Altosaar 《Molecular biotechnology》2009,43(3):232-242
Nucleotide sequence encoding the truncated insecticidal Cry1Ca1 protein from Bacillus thuringiensis was extensively modified based on the codon usage of rice genes. The overall G + C contents of the synthetic cry1Ca1 coding sequence were raised to 65% with an additional bias of enriching for G and C ending codons as preferred by monocots.
The synthetic gene was introduced into the Chinese japonica variety, Xiushui 11, by Agrobacterium-mediated transformation. Transgenic rice plants harboring this gene were highly resistant to Chilo
suppressalis and Spodoptera litura larvae as revealed by insect bioassays. High levels of Cry1Ca1 protein were obtained in the leaves of transgenic rice, which
were effective in achieving 100% mortality of S. litura and C. suppressalis larvae. The levels of Cry1Ca1 expression in the leaves of these transgenic plants were up to 0.34% of the total soluble proteins.
The larvae of C. suppressalis and S.
litura could consume a maximum of 1.89 and 4.89 mm2 of transgenic leaf area whereas the consumption of non-transgenic leaves by these larvae was significantly higher; 58.33 and
61.22 mm2, respectively. Analysis of R1 transgenic plants indicated that the cry1Ca1 was inherited by the progeny plants and provided complete protection against C. suppressalis and S.
litura larvae. 相似文献
4.
Stefanie Kimbacher Ingrid Gerstl Branko Velimirov Sylvia Hagemann 《Molecular genetics and genomics : MGG》2009,282(2):165-172
P transposons belong to the eukaryotic DNA transposons, which are transposed by a cut and paste mechanism using a P-element-coded transposase. They have been detected in Drosophila, and reside as single copies and stable homologous sequences in many vertebrate species. We present the P elements Pcin1, Pcin2 and Pcin3 from Ciona intestinalis, a species of the most primitive chordates, and compare them with those from Ciona savignyi. They showed typical DNA transposon structures, namely terminal inverted repeats and target site duplications. The coding
region of Pcin1 consisted of 13 small exons that could be translated into a P-transposon-homologous protein. C. intestinalis and C. savignyi displayed nearly the same phenotype. However, their P elements were highly divergent and the assumed P transposase from C. intestinalis was more closely related to the transposase from Drosophila melanogaster than to the transposase of C. savignyi. The present study showed that P elements with typical features of transposable DNA elements may be found already at the base of the chordate lineage.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
5.
Lee JH Moon YH Kim N Kim YM Kang HK Jung JY Abada E Kang SS Kim D 《Biotechnology letters》2008,30(4):749-754
The gene encoding sucrose phosphorylase (742sp) in Leuconostoc mesenteroides NRRL B-742 was cloned and expressed in Escherichia coli. The nucleotide sequence of the transformed 742sp comprised an ORF of 1,458 bp giving a protein with calculated molecular mass of 55.3 kDa. 742SPase contains a C-terminal amino acid sequence that is significantly different from those of other Leu. mesenteroides SPases. The purified 742SPase had a specific activity of 1.8 U/mg with a K
m of 3 mM with sucrose as a substrate; optimum activity was at 37°C and pH 6.7. The purified 742SPase transferred the glucosyl
moiety of sucrose to cytosine monophosphate (CMP).
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
6.
The maT clade of transposons is a group of transposable elements intermediate in sequence and predicted protein structure to mariner and Tc transposons, with a distribution thus far limited to a few invertebrate species. We present evidence, based on searches of publicly available databases, that the nematode Caenorhabditis briggsae has several maT-like transposons, which we have designated as CbmaT elements, dispersed throughout its genome. We also describe two additional transposon sequences that probably share their evolutionary history with the CbmaT transposons. One resembles a fold back variant of a CbmaT element, with long (380-bp) inverted terminal repeats (ITRs) that show a high degree (71%) of identity to CbmaT1. The other, which shares only the 26-bp ITR sequences with one of the CbmaT variants, is present in eight nearly identical copies, but does not have a transposase gene and may therefore be cross mobilised by a CbmaT transposase. Using PCR-based mobility assays, we show that CbmaT1 transposons are capable of excising from the C. briggsae genome. CbmaT1 excised approximately 500 times less frequently than Tcb1 in the reference strain AF16, but both CbmaT1 and Tcb1 excised at extremely high frequencies in the HK105 strain. The HK105 strain also exhibited a high frequency of spontaneous induction of unc-22 mutants, suggesting that it may be a mutator strain of C. briggsae. 相似文献
7.
Yan F Peng J Lu Y Lin L Zheng H Chen H Chen J Adams MJ 《Molecular biology reports》2009,36(6):1283-1289
Dicer-like proteins (DCLs) are involved in small RNA-mediated development and viral defense in plants. In model plants, at
least four DCLs have been found and a number of studies have helped to understand their function. However, the function of
the Dicer or DCLs in other plants is still unclear. Here, we report the full-length cDNA sequence of Brassica rapa ssp. chinensis DCL2 (BrDCL2) gene, which contains a 4,179 bp open reading frame (ORF) encoding a protein of 1,392 amino acids. At the 3′ end of BrDCL2, clones with three different lengths of 3′ untranslated region were found. An alternative splice variant of BrDCL2, BrDCL2sv, in which one intron was retained between exon9 and exon10, was also cloned. Because of a change in the coding sequence resulting
in a premature terminal codon, BrDCL2sv was expected to translate a short peptide containing the whole DEXHc domain. 相似文献
8.
Monika Joon Shipra Bhatia Rashmi Pasricha Mridula Bose Vani Brahmachari 《BMC microbiology》2010,10(1):128
Background
The mce operons play an important role in the entry of M. tuberculosis into macrophages and non-phagocytic cells. Their non-redundant function as well as complex regulation is implied by the phenotype of mce mutants. Recently, mce1 operon was found to extend over 13 genes, fadD5 (Rv0166) being the first gene of the operon. The presence of a non-coding sequence of 200 base pairs between Rv0166 and Rv0167 is peculiar to mce1 among the four mce operons of M.tuberculosis. We have examined the function of this region. 相似文献9.
The rpiB gene, encoding ribose-5-phosphate isomerase (RpiB) from Clostridium thermocellum, was cloned and expressed in Escherichia coli. RpiB converted d-psicose into d-allose but it did not convert d-xylose, l-rhamnose, d-altrose or d-galactose. The production of d-allose by RpiB was maximal at pH 7.5 and 65°C for 30 min. The half-lives of the enzyme at 50°C and 65°C were 96 h and 4.7 h,
respectively. Under stable conditions of pH 7.5 and 50°C, 165 g d-allose l−1
was produced without by-products from 500 g d-psicose l−1 after 6 h. 相似文献
10.
Rodríguez-Quiñones F Maguire M Wallington EJ Gould PS Yerko V Downie JA Lund PA 《Archives of microbiology》2005,183(4):253-265
Although many bacteria contain only a single groE operon encoding the essential chaperones GroES and GroEL, examples of bacteria containing more than one groE operon are common. The root-nodulating bacterium Rhizobium leguminosarum contains at least three operons encoding homologues to Escherichia coli GroEL, referred to as Cpn60.1, Cpn60.2 and Cpn60.3, respectively. We report here a detailed analysis of the requirement for and relative levels of these three proteins. Cpn60.1 is present at higher levels than Cpn60.2, and Cpn60.3 protein could not be detected under any conditions although the cpn60.3 gene is transcribed under anaerobic conditions. Insertion mutations could not be constructed in cpn60.1 unless a complementing copy was present, showing that this gene is essential for growth under the conditions used here. Both cpn60.2 and cpn60.3 could be inactivated with no loss of viability, and a double cpn60.2 cpn60.3 mutant was also constructed which was fully viable. Thus only Cpn60.1 is required for growth of this organism.Dedicated to the memory of Professor V. Javier Benedí, 1957–2002 相似文献
11.
The oligopeptide permease (Opp), a protein-dependent ABC transporter, has been found in the genome of Xanthomonas axonopodis pv. citri (Xac), but not in Xanthomonas campestris pv. campestris (Xcc). Sequence analysis indicated that 4 opp genes (oppA, oppB, oppC, oppD/F), located in a 33.8-kbp DNA fragment present only in the Xac genome, are arranged in an operon-like structure and share highest sequence similarities with Streptomyces roseofulvus orthologs. Nonetheless, analyses of the GC content, codon usage, and transposon positioning suggested that the Xac opp operon does not have an exogenous origin. The presence of a stop codon at one of the ATP-binding domains of OppD/F would render the uptake system nonfunctional, but detection of a single polycistronic mRNA and periplasmic OppA in actively growing bacteria suggests that the Opp permease is active and could contribute to the distinct nutritional requirements and host specificities of the two Xanthomonas species. 相似文献
12.
Flower-visiting beetles belonging to three species of Cetoniidae were collected on three mountains near Beijing, China, and yeasts were isolated from the gut of the insects collected. Based
on the 26S rDNA D1/D2 domain and internal transcribed spacer (ITS) region sequence analysis and phenotypic characterization,
four novel anamorphic yeast species located in the Candida albicans/Lodderomyces elongisporus clade were identified from 18 of the strains isolated. The new species and type strains are designated as Candida blackwellae AS 2.3639T (=CBS 10843T), Candida jiufengensis AS 2.3688T (=CBS 10846T), Candida oxycetoniae AS 2.3656T (=CBS 10844T), and Candida pseudojiufengensis AS 2.3693T (=CBS 10847T). C. blackwellae sp. nov. was basal to the branch formed by C. albicans and C. dubliniensis with moderately strong bootstrap support. The closest relative of C. oxycetoniae was L. elongisporus. C. jiufengensis sp. nov. and C. pseudojiufengensis sp. nov. were closely related with each other and formed a branch in a subclade represented by C. parapsilosis and L. elongisporus. 相似文献
13.
14.
Kateryna Zelena Holger Zorn Manfred Nimtz Ralf Günter Berger 《Archives of microbiology》2009,191(5):397-402
For the heterologous expression of the msp2 gene from the edible mushroom Marasmius scorodonius in Escherichia coli the cDNA encoding the extracellular Msp2 peroxidase was cloned into the pBAD III expression plasmid. Expression of the protein
with or without signal peptide was investigated in E. coli strains TOP10 and LMG194. Different PCR products were amplified for expression of the native target protein or a protein
with a signal peptide. Omitting the native stop codon and adding six His-residues resulted in a fusion protein amenable to
immune detection and purification by immobilised metal affinity chromatography. In E. coli the recombinant protein was produced in high yield as insoluble inclusion bodies. The influence of different parameters on
MsP2 refolding was investigated. Active enzyme was obtained by glutathione-mediated oxidation in a medium containing urea,
Ca2+, and hemin. 相似文献
15.
At present, the machinery supporting the viability of organisms possessing nonsense mutations in essential genes is not entirely
understood. Nonsense mutants of Saccharomyces cerevisiae yeast containing a premature translation termination codon in the essential SUP45 gene are known. These strains are viable in the absence of mutant suppressor tRNAs; hence, the existence of alternative mechanisms
providing nonsense suppression and mutant viability is conjectured. Analysis of clones obtained by transformation of a strain
bearing a nonsense-mutant allele of SUP45 with a multicopy yeast genomic library revealed three genes encoding wild-type tRNATyr and four genes encoding wild-type tRNAGln, which increased nonsense mutant viability. Moreover, overexpression of these genes leads to an increase in the amount of
the full-length eRF1 protein in cells and compensates for heat sensitivity in the nonsense mutants. Probable ways of tRNATyr and tRNAGln influence on the increase in the viability of strains with nonsense mutations in SUP45 are discussed. 相似文献
16.
Kakinuma Y Hayashi K Tazumi A Hirayama J Moore JE Millar BC Kuribayashi T Matsuda M 《Folia microbiologica》2011,56(2):159-165
17.
Jin Zhou Ju Chu Yong-Hong Wang Si-Liang Zhang Ying-Ping Zhuang Zhong-Yi Yuan 《World journal of microbiology & biotechnology》2008,24(6):789-796
An intracellular S-adenosylmethionine synthetase (SAM-s) was purified from the fermentation broth of Pichia pastoris GS115 by a sequence chromatography column. It was purified to apparent homogeneity by (NH4)2SO4 fractionation (30–60%), anion exchange, hydrophobic interaction, anion exchange and gel filtration chromatography. HPLC showed
the purity of purified SAM-s was 91.2%. The enzyme was purified up to 49.5-fold with a final yield of 20.3%. The molecular
weight of the homogeneous enzyme was 43.6 KDa, as determined by electro-spray ionization mass spectrometry (ESI-MS). Its isoelectric
point was approximately 4.7, indicating an acidic character. The optimum pH and temperature for the enzyme reaction were 8.5
and 35 °C, respectively. The enzyme was stable at pH 7.0–9.0 and was easy to inactivate in acid solution (pH ≤ 5.0). The temperature
stability was up to 45 °C. Metal ions, such as, Mn2+ and K+ at the concentration of 5 mM had a slight activation effect on the enzyme activity and the Mg2+ activated the enzyme significantly. The enzyme activity was strongly inhibited by heavy metal ions (Cu2+ and Ag2+) and EDTA. The purified enzyme from the transformed Pichia pastoris synthesized S-adenosylmethionine (SAM) from ATP and l-methionine in vitro with a K
m of 120 and 330 μM and V
max of 8.1 and 23.2 μmol/mg/min for l-methionine and ATP, respectively. 相似文献
18.
Hayakawa T Howlader MT Yamagiwa M Sakai H 《Applied microbiology and biotechnology》2008,80(6):1033-1037
Cry4Aa produced by Bacillus thuringiensis is a dipteran-specific toxin and is, therefore, of great interest for developing a bioinsecticide to control mosquitoes.
However, the expression of Cry4Aa in Escherichia coli is relatively low, which is a major disadvantage in its development as a bioinsecticide. In this study, to establish an effective
production system, a 1,914-bp modified gene (cry4Aa-S1) encoding Cry4Aa was designed and synthesized in accordance with the G + C content and codon preference of E. coli genes without altering the encoded amino acid sequence. The cry4Aa-S1 gene allowed a significant improvement in expression level, over five-fold, compared to that of the original cry4Aa gene. The product of the cry4Aa-S1 gene showed the same level of insecticidal activity against Culex pipiens larvae as that from cry4Aa. This suggested that unfavorable codon usage was one of the reasons for poor expression of cry4Aa in E. coli, and, therefore, changing the cry4Aa codons to accord with the codon usage in E. coli led to efficient production of Cry4Aa. Efficient production of Cry4Aa in E. coli can be a powerful measure to prepare a sufficient amount of Cry4Aa protein for both basic analytical and applied researches. 相似文献
19.
Genome predictions based on selected genes would be a very welcome approach for taxonomic studies. We analyzed three genes,
recN, flaA, and ftsY, for determining if these genes are useful tools for systematic analyses in the genus Anoxybacillus. The genes encoding a DNA repair and genetic recombination protein (recN), the flagellin protein (flaA), and GTPase signal docking protein (ftsY) were sequenced for ten Anoxybacillus species. The sequence comparisons revealed that recN sequence similarities range between 61% and 99% in the genus Anoxybacillus. Comparisons to other bacterial recN genes indicated that levels of similarity did not differ from the levels within genus Anoxybacillus. These data showed that recN is not a useful marker for the genus Anoxybacillus. A 550–600-bp region of the flagellin gene was amplified for all Anoxybacillus strains except for Anoxybacillus contaminans. The sequence similarity of flaA gene varies between 61% and 76%. Comparisons to other bacterial flagellin genes obtained from GenBank (Bacillus, Pectinatus, Proteus, and Vibrio) indicated that the levels of similarity were lower (3–42%). Based on these data, we concluded that the variability in this
single gene makes it a particularly useful marker. Another housekeeping gene ftsY suggested to reflect the G+C (mol/mol) content of whole genome was analyzed for Anoxybacillus strains. A mean difference of 1.4% was observed between the G+C content of the gene ftsY and the G+C content of the whole genome. These results showed that the gene ftsY can be used to represent whole G+C content of the Anoxybacillus species. 相似文献
20.
Bourgois TM Van Craeyveld V Van Campenhout S Courtin CM Delcour JA Robben J Volckaert G 《Applied microbiology and biotechnology》2007,76(6):1309-1317
The complete genome sequence of Bacillus subtilis reveals that sequences encoding several hemicellulases are co-localised with a gene (xynD) encoding a putative family 43 glycoside hydrolase that has not yet been characterised. In this work, xynD has been isolated from genomic DNA of B. subtilis subsp. subtilis ATCC 6051 and cloned for cytoplasmatic expression in Escherichia coli. Recombinant XynD (rXynD) was purified using ion-exchange chromatography and gel permeation chromatography. The enzyme had
a molecular mass of approximately 52 kDa, a pI above 9.0 and releases α-l-arabinose from arabinoxylo-oligosaccharides as well as arabinoxylan polymers with varying degree of substitution. Using para-nitrophenyl-α-l-arabinofuranoside as substrate, maximum activity was observed at pH 5.6 and 45°C. The enzyme retained its activity over a
large pH range, while activity was lost after pre-incubation above 50°C. Gas–liquid chromatography and proton nuclear magnetic
resonance spectrometry analysis indicated that rXynD specifically releases arabinofuranosyl groups from mono-substituted C-(O)-2 and C-(O)-3 xylopyranosyl residues on the xylan backbone. As rXynD did not display endoxylanase, xylosidase or arabinanase activity
and was inactive on arabinan, we conclude that this enzyme is best described as an arabinoxylan arabinofuranohydrolase. 相似文献