Abstract:
:Type IIb heat-labile enterotoxin (LT-IIb) is produced by Escherichia coli 41. Restriction fragments of total cell DNA from strain 41 were cloned into a cosmid vector, and one cosmid clone that encoded LT-IIb was identified. The genes for LT-IIb were subcloned into a variety of plasmids, expressed in minicells, sequenced, and compared with the structural genes for other members of the Vibrio cholerae-E. coli enterotoxin family. The A subunits of these toxins all have similar ADP-ribosyltransferase activity. The A genes of LT-IIa and LT-IIb exhibited 71% DNA sequence homology with each other and 55 to 57% homology with the A genes of cholera toxin (CT) and the type I enterotoxins of E. coli (LTh-I and LTp-I). The A subunits of the heat-labile enterotoxins also have limited homology with other ADP-ribosylating toxins, including pertussis toxin, diphtheria toxin, and Pseudomonas aeruginosa exotoxin A. The B subunits of LT-IIa and LT-IIb differ from each other and from type I enterotoxins in their carbohydrate-binding specificities. The B genes of LT-IIa and LT-IIb were 66% homologous, but neither had significant homology with the B genes of CT, LTh-I, and LTp-I. The A subunit genes for the type I and type II enterotoxins represent distinct branches of an evolutionary tree, and the divergence between the A subunit genes of LT-IIa and LT-IIb is greater than that between CT and LT-I. In contrast, it has not yet been possible to demonstrate an evolutionary relationship between the B subunits of type I and type II heat-labile enterotoxins. Hybridization studies with DNA from independently isolated LT-II producing strains of E. coli also suggested that additional variants of LT-II exist.
journal_name
J Bacterioljournal_title
Journal of bacteriologyauthors
Pickett CL,Twiddy EM,Coker C,Holmes RKdoi
10.1128/jb.171.9.4945-4952.1989subject
Has Abstractpub_date
1989-09-01 00:00:00pages
4945-52issue
9eissn
0021-9193issn
1098-5530journal_volume
171pub_type
杂志文章abstract::Mated cultures of Blakeslea trispora, grown in a potato extract-glucose-thiamine medium, produced 10 to 15 times more beta-carotene than either unmated culture. Mated, but not unmated, cultures produced a family of compounds (beta factor) which stimulated carotenogenesis in unmated cultures. In fact, carotenogenesis w...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.95.2.426-432.1968
更新日期:1968-02-01 00:00:00
abstract::The Saccharomyces cerevisiae mating hormone a-factor has been difficult to isolate reproducibly in sufficient yields by methods using ion-exchange chromatography, probably because of its pronounced hydrophobicity. In this work, a hydrophobic adsorbent (Amberlite XAD-2), in an insoluble bead from, was used to isolate l...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.151.3.1153-1161.1982
更新日期:1982-09-01 00:00:00
abstract::Cytochrome bd oxidase operons from more than 50 species of bacteria contain a short gene encoding a small protein that ranges from ∼30 to 50 amino acids and is predicted to localize to the cell membrane. Although cytochrome bd oxidases have been studied for more than 70 years, little is known about the role of this sm...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00324-13
更新日期:2013-08-01 00:00:00
abstract::A number of independently derived uracil-requiring mutant strains of the parent strain 168 were mapped by inter-mutant transformation crosses. Only a few of these mutant strains were found to be transformable. Studies were performed in which these transformable uracil-requiring mutant strains were used as the recipien...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.116.2.577-581.1973
更新日期:1973-11-01 00:00:00
abstract::We describe the derivation of two strains of Salmonella typhimurium LT2 which are r- m+ for all three of the known chromosomal genes for the restriction and modification of DNA, hsdLT, hsdSA, and hsdSB; the strains were designated LB5000 and LB5010. LB5000 is a smooth derivative sensitive to phage P22; LB5010 is a gal...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.156.1.471-474.1983
更新日期:1983-10-01 00:00:00
abstract::Pyridine-2,6-bis(thiocarboxylate) (PDTC), produced by certain pseudomonads, is a sulfur-containing siderophore that binds iron, as well as a wide range of transition metals, and it affects the net hydrolysis of the environmental contaminant carbon tetrachloride. The pathway of PDTC biosynthesis has not been defined. H...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00528-13
更新日期:2013-09-01 00:00:00
abstract::Using a transcriptional fusion to the lacZ gene, we have analyzed the anaerobic regulation of the hydrogenase 1 (hya) operon in response to different anaerobic growth conditions and to mutations in regulatory genes. We found that the transcription of the hya operon was induced when the growth condition was changed fro...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.176.17.5423-5428.1994
更新日期:1994-09-01 00:00:00
abstract::A ubiquinone-deficient mutant, carrying mutations in two genes affecting ubiquinone biosynthesis, has been used, in comparison with a normal strain, to determine the sequence of some of the components of the electron transport chain of Escherichia coli. The amounts of cytochromes reduced during aerobic steady-state co...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.133.2.477-484.1978
更新日期:1978-02-01 00:00:00
abstract::Bacterial uptake of phosphate is usually accomplished via high-affinity transporters that are commonly regulated by two-component systems, which are activated when the concentration of phosphate is low. Mycobacterium smegmatis possesses two such transporters, the widely distributed PstSCAB system and PhnDCE, a transpo...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.01965-14
更新日期:2014-10-01 00:00:00
abstract::The pdxK and pdxY genes have been found to code for pyridoxal kinases, enzymes involved in the pyridoxal phosphate salvage pathway. Two pyridoxal kinase structures have recently been published, including Escherichia coli pyridoxal kinase 2 (ePL kinase 2) and sheep pyridoxal kinase, products of the pdxY and pdxK genes,...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00122-06
更新日期:2006-06-01 00:00:00
abstract::Bacterial cells sense the extracellular environment and adapt to that environment by activating gene regulation circuits, often by means of signaling molecules. The Serratia marcescens hemophore is a signaling molecule that acts as an extracellular heme-scavenging protein. The heme-loaded hemophore interacts with its ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.188.9.3357-3364.2006
更新日期:2006-05-01 00:00:00
abstract::In coupling the reducing power of illuminated chloroplasts to the nitrogenase from photosynthetically grown Rhodospirillum rubrum cells, one of the native ferredoxins. FdI, was found to be three times more effective than FdII. ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.121.2.743-745.1975
更新日期:1975-02-01 00:00:00
abstract::Plasmid pE194 has been shown to be rescued by integration after cultivation of infected Bacillus subtilis recE4 cells at a restrictive high temperature. The plasmid is also spontaneously excised from the chromosome at a low frequency by precise or imprecise excision (J. Hofemeister, M. Israeli-Reches, and D. Dubnau, M...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.174.21.6997-7002.1992
更新日期:1992-11-01 00:00:00
abstract::Ferric reductase activity was examined in Azotobacter vinelandii and was found to be located in the cytoplasm. The specific activities of soluble cell extracts were not affected by the iron concentration of the growth medium; however, activity was inhibited by the presence of Zn2+ during cell growth and also by the ad...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.171.7.4031-4037.1989
更新日期:1989-07-01 00:00:00
abstract::NAD-independent lactate dehydrogenases are commonly thought to be responsible for lactate utilization during the stationary phase of aerobic growth in Lactobacillus plantarum. To substantiate this view, we constructed single and double knockout mutants for the corresponding genes, loxD and loxL. Lactate-to-acetate con...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.186.19.6661-6666.2004
更新日期:2004-10-01 00:00:00
abstract::The mannans of Saccharomyces chevalieri, S. italicus, S. diastaticus, and S. carlsbergensis, were acetolyzed, and the fragments were separated by gel filtration. All gave similar acetolysis fingerprints, which were distinguished from S. cerevisiae by the presence of a pentasaccharide component in addition to the mono-...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.117.2.461-467.1974
更新日期:1974-02-01 00:00:00
abstract::The structure and composition of the cell walls of hyphae of Neurospora crassa were investigated by electron microscopy, chemical analysis, and X-ray diffraction both before and after progressive enzymatic degradation by snail gut enzymes, chitinase, and trypsin. The wall consists of two phases: randomly disposed skel...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.94.1.202-212.1967
更新日期:1967-07-01 00:00:00
abstract::We screened Salmonella typhimurium, Citrobacter freundii, Klebsiella pneumoniae, Shigella boydii, and many isolates of Escherichia coli for DNA sequences homologous to those encoding each of two unrelated type I restriction and modification systems (EcoK and EcoA). Both K- and A-related hsd genes were identified, but ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.170.4.1775-1782.1988
更新日期:1988-04-01 00:00:00
abstract::Due in large part to their ability to facilitate the diffusion of a diverse range of solutes across the outer membrane (OM) of Gram-negative bacteria, the porins represent one of the most prominent and important bacterial membrane protein superfamilies. Notably, for the Gram-negative bacterium Desulfovibrio vulgaris H...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00286-17
更新日期:2017-10-31 00:00:00
abstract::Inducible cat and erm genes are regulated by translational attenuation. In this regulatory model, gene activation results from chloramphenicol- or erythromycin-dependent stalling of a ribosome at a precise site in the leader region of cat or erm transcripts. The stalled ribosome is believed to destabilize a downstream...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.172.11.6282-6290.1990
更新日期:1990-11-01 00:00:00
abstract::The gene (entD) encoding staphylococcal enterotoxin D (SED) has been located on a 27.6-kilobase penicillinase plasmid designated pIB485. This plasmid was present in all SED-producing strains tested. The entD gene was cloned on a 2.0-kilobase DNA fragment and was expressed in Escherichia coli. Sequence analysis of this...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.171.9.4799-4806.1989
更新日期:1989-09-01 00:00:00
abstract::In Escherichia coli, rotation of the flagellar motor has been shown to depend upon electrostatic interactions between charged residues of the stator protein MotA and the rotor protein FliG. These charged residues are conserved in the Na+-driven polar flagellum of Vibrio alginolyticus, but mutational studies in V. algi...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.188.4.1466-1472.2006
更新日期:2006-02-01 00:00:00
abstract::Flagellar biogenesis and hence motility of Vibrio fischeri depends upon the presence of magnesium. In the absence of magnesium, cells contain few or no flagella and are poorly motile or nonmotile. To dissect the mechanism by which this regulation occurs, we screened transposon insertion mutants for those that could mi...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00728-06
更新日期:2006-12-01 00:00:00
abstract::We have cloned three copies of a repeated DNA segment from Borrelia burgdorferi sensu stricto strain B31, present on both circular and linear plasmids of this and other B. burgdorferi sensu lato strains. The DNA sequences are characterized by a highly homologous segment containing two open reading frames (ORFs), ORF-A...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.178.8.2287-2298.1996
更新日期:1996-04-01 00:00:00
abstract:UNLABELLED:The transmembrane Tsr protein of Escherichia coli mediates chemotactic responses to environmental serine gradients. Serine binds to the periplasmic domain of the homodimeric Tsr molecule, promoting a small inward displacement of one transmembrane helix (TM2). TM2 piston displacements, in turn, modulate the s...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00274-15
更新日期:2015-08-01 00:00:00
abstract::The Rnf complex is a respiratory enzyme that catalyzes the oxidation of reduced ferredoxin to the reduction of NAD+, and the negative free energy change of this reaction is used to generate a transmembrane ion gradient. In one class of anaerobic acetogenic bacteria, the Rnf complex is believed to be essential for ener...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00357-18
更新日期:2018-10-10 00:00:00
abstract::Alicyclobacillus acidocaldarius strain Tc-4-1 was initially isolated from a hot spring in Tengchong, China. This organism is both thermophilic and acidophilic. It can produce heat- and acid-stable enzymes, such as amylase and esterase, which may be important in industry. Here we report the whole genome sequence of the...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.05709-11
更新日期:2011-10-01 00:00:00
abstract::Streptococcus equi subsp. zooepidemicus is an opportunistic pathogen. It has caused a very large economic loss in the swine industry of China and has become a threat to human health. We announce the complete genome sequence of S. equi subsp. zooepidemicus strain ATCC 35246, which provides opportunities to understand i...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.05700-11
更新日期:2011-10-01 00:00:00
abstract::Several authors have suggested that the SOS-associated (sfiA-dependent) system of division inhibition, normally induced by perturbations of DNA replication, also regulates steady-state (unperturbed) cell division. The present work shows that mean cell mass is identical in sfiA+ and sfiA mutant cultures during steady-s...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.153.2.1072-1074.1983
更新日期:1983-02-01 00:00:00
abstract::A gene required for growth and viability in recA mutants of Escherichia coli K-12 was identified. This gene, rdgB (for Rec-dependent growth), mapped near 64 min on the E. coli genetic map. In a strain carrying a temperature-sensitive recA allele, recA200, and an rdgB mutation, DNA synthesis but not protein synthesis c...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.169.9.4203-4210.1987
更新日期:1987-09-01 00:00:00