共查询到20条相似文献,搜索用时 31 毫秒
1.
Analysis of the distribution of 35S-sulfate and 14C-glutamate in major biochemical components of the two marine bacteria, Pseudomonas halodurans and Alteromonas luteo-violaceus, was compared with cell density and total cellular protein during exponential growth in batch culture. For both organisms, the sulfur distribution was restricted principally to the low molecular weight organic and protein fractions, which together accounted for over 90% of the total sulfur. Carbon was more widely distributed, with these two fractions containing only 70% of the total label.Growth rate constants calculated from increases in cell numbers, protein, and 35S and 14C in the various fractions indicated nearly balanced growth in A. luteo-violaceus, with constants derived from all biosynthetic parameters agreeing within 5% during the exponential phase. In contrast, protein synthesis and 35S incorporation into residue protein constants were 30% higher than constants derived from cell counts and incorporation of 14C in P. halodurans. Therefore the cellular protein content P. halodurans varied over a two-fold range, with maximum protein per cell in the late exponential phase. A distinct reduction in the rate constants for total protein and 35S incorporation into residue protein foreshadowed entry into the stationary phase more than one generation before other parameters.Incorporation of 35S-sulfate into residue protein paralleled protein synthesis in both bacteria. The weight percent S in protein agreed well with the composition of an average protein derived from the literature. Sulfur incorporation into protein may be a useful measurement of marine bacterial protein synthesis.Abbreviations L.M.W.
low molecular weight
- TCA
trichloroacetic acid
- CFU
colony forming unit 相似文献
2.
Raúl Espinosa Evelyn Caballero Alexis Musacchio Ricardo Silva 《Biotechnology letters》2002,24(5):343-346
P64k is a Neisseria meningitidis high molecular weight protein present in meningococcal vaccine preparations. The lpdA gene, codifying for this protein, was cloned in Escherichia coli and the P64k protein was expressed in Escherichia coli K12 W3110 under the control of the tryptophan promoter. The recombinant bacteria were grown in batch or fed-batch cultures. P64k was expressed as an intracellular soluble form at about 40% of the total cellular protein. A final productivity of 215 mg l–1 h–1 and 11 g cell dry wt l–1 were obtained when the fed-batch culture conditions were optimised, compared to 30% of total protein, and a productivity of 76 mg l–1 h–1 and 5.1 g cell dry wt l–1 in batch cultivation. 相似文献
3.
Ayako Kamei Shizue Yoshihara Takashi Yuasa Xiaoxing Geng Masahiko Ikeuchi 《Current microbiology》2003,46(4):0296-0301
On the basis of the genome sequence, the unicellular motile cyanobacterium Synechocystis sp. PCC 6803 harbors seven putative genes for eukaryotic-type protein kinase belonging to Pkn2 subfamily (spkA ∼ spkG). Previously, SpkA was shown to have protein kinase activity and to be required for cell motility. Here, the role of the
spkB was examined. The spkB gene was expressed in Escherichia coli as a fusion protein with His-tag, and the protein was purified by Ni2+ affinity chromatography. The eukaryotic-type protein kinase activity of the expressed SpkB was demonstrated as autophosphorylation
to itself and phosphorylation of the general substrate proteins. SpkB showed autophosphorylation activity in the presence
of both Mg2+ and Mn2+, but not in Ca2+. Phenotype analysis of spkB disruptant of Synechocystis revealed that spkB is required for cell motility, but not for phototaxis. These results suggest that SpkB is the eukaryotic-type protein kinase,
which regulates cellular motility via protein phosphorylation like SpkA.
Received: 8 June 2002 / Accepted: 5 July 2002 相似文献
4.
We describe genetic interactions between mutations in mgr, asp, and polo, genes required for the correct behaviour of the spindle poles in Drosophila. The phenotype of a polo
1
mgr double mutant is more similar to mgr than polo
1
, but the frequency of circular monopolar figures (CMFs) seen with either mutant alone is additive, suggesting that the two
gene products are required for independent functions in the formation of bipolar spindles. The asp
E3
mgr double mutant arrests much earlier in development than either mutant alone, indicative of a strong block to cell proliferation.
We discuss whether the lack of microtubular structures in these cells reflects an extended mitotic arrest, or if it is a more
direct consequence of the double mutant combination. A polo
1
asp
E3
double mutant shows a dramatic synergistic increase in mitotic frequency. The loss of CMFs normally associated with the polo
1
phenotype suggests that the Asp microtubule-associated protein is required to maintain the structure of spindle poles. We
speculate that Asp protein might be a substrate for the serine-threonine protein kinase encoded by polo.
Received: 8 August 1998 / Accepted: 13 September 1998 相似文献
5.
Protein splicing is a precise post-translational process mediated by inteins. Inteins are intervening proteins that cleave
themselves from a precursor protein while joining the flanking sequences. Here we report the 15N, 13C, and 1H chemical shift assignments of the intein from DNA polymerase II of Pyrococcus abyssi (Pab PolII intein), which has been recombinantly overexpressed and isotopically labeled. The NMR assignments of Pab PolII intein are essential for solution structure determination and protein dynamics study. 相似文献
6.
Rao J DiGiandomenico A Artamonov M Leitinger N Amin AR Goldberg JB 《Cellular immunology》2011,(2):95-102
This study describes the role of “inflammatory” oxidized (Ox) phospholipids in regulation of rahU (PA0122) expression and biofilm formation in Pseudomonas aeruginosa (383) wild type (rahU+) and rahU mutant (rahU−) strains. Functional analysis of RahU protein from P. aeruginosa in presence of Ox-phospholipids show: (a) LysoPC modulates RahU gene/and protein expression in rahU+ cells; (b) rahU promoter activity is increased by lysoPC and inhibited by PAPC, Ox-PAPC and arachidonic acid; the latter inhibitory effect can be reversed by lysoPC, which was enzymatically derived from PAPC; (c) biofilm formation increased in rahU− cells as compared to rahU+; and (d) inhibition of rahU promoter activity by PAPC and AA (but not lysoPC) showed significantly augmented biofilm formation in rahU+ but not in rahU− cells. This study shows that host derived Ox-phospholipids affect P. aeruginosa-rahU gene and protein expression, which in turn modulates biofilm formation. The accompanying paper describes the role of RahU protein in eukaryotic-host cells. 相似文献
7.
Eiko Otaka Takuzi Itoh Syozo Osawa Kentaro Tanaka Mikio Tamaki 《Molecular & general genetics : MGG》1972,114(1):14-22
Summary Chromatographic analyses on a Dowex 50x8 column of tryptic digests of the mutationally altered 50-8 protein component from several erythromycin resistant (ery
r) mutants of Escherichia coli and Escherichia freundii have been performed. It was found that (1) the difference in the elution profile of the altered components detected with carboxymethyl cellulose column chromatography reflects the difference in their amino acid sequence, (2) the structural change(s) of the 50-8 protein from three E. coli ery
r mutants examined seems to exist only in the same single peptide fragment and (3) the primary structure of the 50-8(R) protein of E. freundii (ery
s: wild type) differs from that of E. coli Q13 (ery
s) and the structural change in 50-8(R) component of E. freundii caused by the ery
r mutation was found to take place in different peptide fragments from that in which the mutational change of the E. coli 50-8 component occurred. 相似文献
8.
Kai U. Cormann Masahiko Ikeuchi Matthias Rögner Marc M. Nowaczyk Raphael Stoll 《Biomolecular NMR assignments》2009,3(2):247-249
Photosystem II (PSII) is a large membrane protein complex that uses light to split water into molecular oxygen, protons, and
electrons. Here we report the 1H, 15N and 13C backbone chemical shift assignments for the Psb27 protein of Photosystem II from Synechocystis PCC 6803. These assignments will now provide the basis for the structural analysis of the Psb27 protein. 相似文献
9.
The phytopathogenic fungi Colletotrichum circinans, Fusarium solani, and Rhizoctonia solani were incubated in aerated (0, 0.5, 1 dm3 min–1) potato dextrose broth (PDB) or Czapek-Dox broth (CDB), under 0-, 12- or 24-h photoperiods. Greater dry mass was produced in PDB. Higher air flows improved dry mass of F. solani and R. solani. The 24-h photoperiod improved F. solani dry mass. Except for F. solani, which was not affected, incubation in PDB increased protein content. The no air treatment increased protein content in F. solani, 0.5 dm3 min–1 produced the highest protein content in R. solani, but air flow-rate did not affect C. circinans. Incubation in the dark produced the lowest protein content in C. circinans, the highest under the 24-h photoperiod for R. solani, and photoperiod did not affect protein content in F. solani. Protein content in R. solani, incubated in CDB, was lowest at the 0 dm3 min–1 air flow at all photoperiods. Molecular masses of most proteins were under 30 kDa, and numbers of bands in SDS-PAGE gels varied with air flow. In CDB, especially under 12- or 24-h photoperiods, proteins in F. solani were between 1.6 and 310 kDa. For R. solani in PDB, at 0.5 dm3 min–1 air flow and 12-h light, proteins were between 6 and 81 kDa. 相似文献
10.
11.
Summary Inhibitors of, and radioactive substrates for, protein synthesis were introduced into germinating pea (Pisum sativum L.) seeds, and protein synthesis was allowed to proceed in vivo. Subsequent analyses of subcellular fractions showed the following: Cycloheximide strongly inhibited the incorporation of [14C]leucine into both mitochondrial and cytoplasmic proteins. d-Threo-chloramphenicol and erythromycin did not affect cytoplasmic protein synthesis, but partially inhibited mitochondrial protein synthesis. These results suggest that most of the new mitochondrial proteins were originally synthesized in the cytoplasm. Actinomycin D did not appreciably affect the initial incorporation of [14C]leucine into either mitochondrial or cytoplasmic proteins, suggesting that information (mRNA) concerning the initially synthesized proteins may be present in the quiescent seeds. The lack of appreciable incorporation of [3H]thymidine into mitochondrial DNA supported our previons report that mitochondria may not be synthesized de novo in pea cotyledons. 相似文献
12.
An iron-sulfur cluster assembly protein, IscU, is encoded by the operon iscSUA in Acidithiobacillus ferrooxidans. The gene of IscU was cloned and expressed in Escherichia coli. The protein was purified by one-step affinity chromatography to homogeneity. The protein was in apo-form, the [Fe2S2] cluster could be assembled in apoIscU with Fe2+ and sulfide in vitro, and in the presence of IscA and IscS, the IscU could utilize l-cysteine and Fe2+ to synthesize [Fe2S2] cluster in the protein. Site-directed mutagenesis for the protein revealed that Cys37, Asp39, Cys63 and Cys106 were involved
in ligating with the [Fe2S2] cluster. 相似文献
13.
Summary Kinetic analysis of induction of recA protein synthesis after U.V. irradiation does not show correspondence with the kinetics of division inhibition in lon
+ and lon
- strains, but there is correlation between induction and DNA repair activity. Protein X is stable and identical in both lon
+ and lon
- strains. When the induction of recA protein after U.V. is drastically reduced by rifampicin treatment, no effect on the kinetics of division inhibition is observed. 相似文献
14.
Hwa-Chain R. Wang 《Journal of cellular physiology》1996,168(1):87-96
Two distinct stages in regulation of protein kinases are detectable upon cellular transformation of CEF induced by pp60v-src. Upon cellular transformation induced by ts v-src mutants, the kinase activities of Mek and p42Erk are rapidly induced at the early stage and significantly decreased at the late stage of cellular transformation. In contrast, a novel p63SAMK is partially activated at the early stage and is fully activated at the late stage of cellular transformation. However, p90RSK is activated through the entire course of cellular transformation. In this study, I detect a transient down-regulation of p90RSK activity that is inducible in cultures at the late stage of the src-induced cellular transformation by an increase of extracellular pH value from 7 to 8 and unidentified components in DMEM, but not in cultures which are at the early stage. Concomitant with down-regulation of p90RSK activity, the kinase activities of Mek, p42Erk, and p63SAMK are also down-regulated. Blockage of down-regulation of p90RSK activity by pretreatment of cells with different phosphatase inhibitors correlates with blockage of the down-regulation of either p42Erk or p63SAMK activity. Multiple pathways appear to involve in regulation of p90RSK activity. The discrepancy in regulation of protein kinase activity between the early and late stages of cellular transformation induced by pp60src may indicate a change in signaling cascades during the progress of cellular transformation. The induction of the down-regulation event in this study may provide a new approach to investigate the regulation not only of protein kinases but also phosphatases in transformed cells. © 1996 Wiley Liss, Inc. 相似文献
15.
Galactosemic cataracts are characterized by electrolyte disturbances resulting in osmotic imbalance and loss of transparency.
We have studied the defensive role of quercetin, a bioflavonoid, against the alterations of calcium (Ca2+), sodium (Na+), and potassium (K+) concentrations in galactose-induced cataract in a rodent model. The experimental study was conducted on weanling male Wistar
rats with an average body weight of 34 ± 0.9 g. Different groups received normal stock AIN 93 diet (group A, n = 8), AIN 93 diet with 30% galactose (group B, n = 8), and AIN 93 diet with 30% galactose + quercetin at 400 mg/100 g diet (group C, n = 8). Aldose reductase activity and protein content and concentrations of Ca2+, Na+, and K+ were determined in normal and cataractous lenses. Treatment with quercetin resulted in a significant decrease in Na+ and Ca2+ and aldose reductase levels and an increase in K+ and protein levels in galactosemic cataractous lenses. These results imply that inclusion of quercetin contributes to lens
transparency through the maintenance of characteristic osmotic ion equilibrium and protein levels of the lens. 相似文献
16.
17.
Inés Castrillo Jorge Alegre-Cebollada Álvaro Martínez del Pozo José G. Gavilanes Jorge Santoro Marta Bruix 《Biomolecular NMR assignments》2009,3(1):5-7
Sticholysin I is an actinoporin, a pore forming toxin, of 176 aminoacids produced by the sea anemone Stichodactyla heliantus. Isotopically labelled 13C/15N recombinant protein was produced in E. coli. Here we report the complete NMR 15N, 13C and 1H chemical shifts assignments of Stn I at pH 4.0 and 25°C (BMRB No. 15927). 相似文献
18.
Yaël Grosjean Fabien Lacaille Angel Acebes Johanna Clemencet Jean‐Franois Ferveur 《Developmental neurobiology》2003,55(1):1-13
The PGal4 transposon inserted upstream of the pan‐neural gene prospero (pros) causes several neural and behavioral defects in the Voila1 strain. The precise excision of the transposon simultaneously rescued all these defects whereas its unprecise excision created new prosV alleles, including the null allele prosV17. Here, we describe the relationship between the genetic structure of pros locus, larval locomotion, and larval gustatory response. These two behaviors showed varying degrees of variation depending upon the pros allele. We also found a good relation between behavioral alteration, the level of Pros protein in the embryo, and the degree of disorganization in the larval neuromuscular junction. These data suggest that the complete development of the nervous system requires a full complement of Pros, and that a gradual decrease in the levels of this protein can proportionally alter the development and the function of the nervous system. © 2003 Wiley Periodicals, Inc. J Neurobiol 55: 1–13, 2003 相似文献
19.
Mycobacterium tuberculosis Rv0228, a membrane protein, is predicted as a drug target through computational methods. MSMEG_0319 (MS0319) in Mycobacterium smegmatis mc2155 is the ortholog of Rv0228. To study the effect of MS0319 protein on M. smegmatis, an MS0319 gene knockout strain (ΔMS0319) was generated via a homologous recombination technique in this study. The results showed that the lack of MS0319 protein in mc2155 cells led to the loss of viability at nonpermissive temperature. Scanning electron microscopy and transmission electron microscopy observations showed drastic changes in cellular shape especially cell wall disruption in ΔMS0319 cells. Proteomic analysis of ΔMS0319 cells through LC‐MS/MS revealed that 462 proteins had changes in their expressions by lacking MS0319 protein. The M. tuberculosis orthologs of these 462 proteins were found through BLASTp search and functional clustering and metabolic pathway enrichment were performed on the orthologs. The results revealed that most of them were enzymes involved in metabolism of carbohydrates and amino acids, indicating that Rv0228 played an important role in cellular metabolism. All these results suggested Rv0228 as a potential target for development of antituberculosis drugs. 相似文献
20.
We report the 1H, 13C, and 15N chemical shift assignments of both oxidized and reduced forms of an abundant periplasmic c-type cytochrome, designated ApcA, isolated from the acidophilic gram-negative facultatively anaerobic metal-reducing alphaproteobacterium
Acidiphilium cryptum. These resonance assignments prove that ApcA is a monoheme cytochrome c
2 and the product of the Acry_2099 gene. An absence of resonance peaks in the NMR spectra for the 21N-terminal residues suggests
that a predicted N-terminal signal sequence is cleaved. We also describe the preparation and purification of the protein in
labeled form from laboratory cultures of A. cryptum growing on 13C- and 15N- labeled substrates. 相似文献