Abstract:
:Many gram-negative bacteria harbor a copper/zinc-containing superoxide dismutase (CuZnSOD) in their periplasms. In pathogenic bacteria, one role of this enzyme may be to protect periplasmic biomolecules from superoxide that is released by host phagocytic cells. However, the enzyme is also present in many nonpathogens and/or free-living bacteria, including Escherichia coli. In this study we were able to detect superoxide being released into the medium from growing cultures of E. coli. Exponential-phase cells do not normally synthesize CuZnSOD, which is specifically induced in stationary phase. However, the engineered expression of CuZnSOD in growing cells eliminated superoxide release, confirming that this superoxide was formed within the periplasm. The rate of periplasmic superoxide production was surprisingly high and approximated the estimated rate of cytoplasmic superoxide formation when both were normalized to the volume of the compartment. The rate increased in proportion to oxygen concentration, suggesting that the superoxide is generated by the adventitious oxidation of an electron carrier. Mutations that eliminated menaquinone synthesis eradicated the superoxide formation, while mutations in genes encoding respiratory complexes affected it only insofar as they are likely to affect the redox state of menaquinone. We infer that the adventitious autoxidation of dihydromenaquinone in the cytoplasmic membrane releases a steady flux of superoxide into the periplasm of E. coli. This endogenous superoxide may create oxidative stress in that compartment and be a primary substrate of CuZnSOD.
journal_name
J Bacterioljournal_title
Journal of bacteriologyauthors
Korshunov S,Imlay JAdoi
10.1128/JB.00554-06subject
Has Abstractpub_date
2006-09-01 00:00:00pages
6326-34issue
17eissn
0021-9193issn
1098-5530pii
188/17/6326journal_volume
188pub_type
杂志文章abstract::As part of an analysis of the conjugative transfer genes associated with the expression of F pili by plasmid F, we have investigated the physical location of the traC and traW genes. We found that plasmid clones carrying a 2.95-kilobase EcoRI-EcoRV F transfer operon fragment were able to complement transfer of F lac t...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.169.11.5119-5124.1987
更新日期:1987-11-01 00:00:00
abstract::In Bacillus thuringiensis, a novel N-acetylmuramoyl-L-alanine amidase gene (named cwlB) was detected, and the CwlB protein was purified and characterized. Reverse transcription-PCR (RT-PCR) results indicated that cwlB and an upstream gene (named cwlA) formed one transcriptional unit. 5' rapid amplification of cDNA end...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00112-13
更新日期:2013-06-01 00:00:00
abstract::The structural gene coding for the delta 5-3-ketosteroid isomerase (KSI) of Pseudomonas putida biotype B has been cloned, and its entire nucleotide sequence has been determined by a dideoxynucleotide chain termination method. A 2.1-kb DNA fragment containing the ksi gene was cloned from a P. putida biotype B genomic l...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.176.21.6672-6676.1994
更新日期:1994-11-01 00:00:00
abstract::Cells of Ureaplasma urealyticum that were prepared by a ruthenium red technique demonstrated an extramembranous layer of polyanions of about 15 to 30 nm in width. Application of the concanavalin A-iron dextran strain indicated that the outer surface of this layer contained glucosyl-like residues. ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.128.2.658-660.1976
更新日期:1976-11-01 00:00:00
abstract::The endoplasmic reticulum from Neurospora crassa was identified by monitoring the activity of the putative enzyme marker phosphatidylcholine glyceride transferase. After differential centrifugation of a cell homogenate, phosphatidylcholine glyceride transferase activity initially copurified with plasma membrane H+-ATP...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.156.1.362-368.1983
更新日期:1983-10-01 00:00:00
abstract::Functional domains in the RepI replication initiator protein have been identified by classical and site-directed mutagenesis techniques. Mutations conferring an increase in plasmid copy number contained alterations in a key position of a putative helix-turn-helix DNA binding motif. The mutations did not appear to affe...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.175.11.3563-3569.1993
更新日期:1993-06-01 00:00:00
abstract::Horizontal gene transfer by conjugation plays a major role in bacterial evolution, allowing the acquisition of new traits, such as virulence and resistance to antibacterial agents. With the increased antibiotic resistance in bacterial pathogens, a better understanding of how bacteria modulate conjugation under changin...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.02279-14
更新日期:2015-03-01 00:00:00
abstract::Members of all four families of methanogenic bacteria were analyzed for polyamine concentrations. High-performance liquid chromatography analysis of dansylated cell extracts revealed typical polyamine patterns for each family. Members of Methanobacteriaceae (family I) were characterized by very low polyamine concentra...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.154.3.1315-1322.1983
更新日期:1983-06-01 00:00:00
abstract::The autolytic capacity of Streptococcus faecium (S. faecalis ATCC 9790) varied during synchronous cell division. This phenomenon was initially observed in rapidly dividing populations (TD=30 to 33 min) synchronized by a combination of induction and size selection techniques. To minimize the problems inherent in studie...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.133.2.822-829.1978
更新日期:1978-02-01 00:00:00
abstract:UNLABELLED:Ileal lesions of patients with Crohn's disease are colonized by adherent-invasive Escherichia coli (AIEC), which is able to adhere to and to invade intestinal epithelial cells (IEC), to replicate within macrophages, and to form biofilms on the surface of the intestinal mucosa. Previous analyses indicated the...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.02499-14
更新日期:2015-04-01 00:00:00
abstract::This is the first study of sporogenesis in Streptomyces carried out on a relatively high number of species (seven) which allows us, using also previously published results, to establish a general picture of this process. In the sporogenesis of Streptomyces two basic stages can be considered: the sporulation septum syn...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.127.3.1443-1454.1976
更新日期:1976-09-01 00:00:00
abstract::SecA signal peptide interaction is critical for initiating protein translocation in the bacterial Sec-dependent pathway. Here, we have utilized the recent nuclear magnetic resonance (NMR) and Förster resonance energy transfer studies that mapped the location of the SecA signal peptide-binding site to design and isolat...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.06150-11
更新日期:2012-01-01 00:00:00
abstract::The P(styA) promoter of Pseudomonas sp. strain Y2 controls expression of the styABCD genes, which are required for the conversion of styrene to phenylacetate, which is further catabolized by the products of two paa gene clusters. Two PaaX repressor proteins (PaaX1 and PaaX2) regulate transcription of the paa gene clus...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00176-06
更新日期:2006-07-01 00:00:00
abstract::With a DNA fragment from within the region encoding the transport functions for K1 production as a hybridization probe in Southern blot experiments, homologous DNA sequences were detected in the DNA from Escherichia coli strains producing K5, K7, K92, and K100 capsular polysaccharides. No homology with the laboratory ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.168.3.1228-1233.1986
更新日期:1986-12-01 00:00:00
abstract::Autolysin-defective pneumococci treated with inhibitory concentrations of penicillin and other beta-lactam antibiotics continued to produce non-cross-linked peptidoglycan and cell wall teichoic acid polymers, the majority of which were released into the surrounding medium. The released cell wall polymers were those sy...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.157.2.507-513.1984
更新日期:1984-02-01 00:00:00
abstract::MobB is a small protein encoded by the broad-host-range plasmid R1162 and required for efficient mobilization of its DNA during conjugation. The protein was shown previously to stabilize the relaxosome, the complex of plasmid DNA and mobilization proteins at the origin of transfer (oriT). We have generated in-frame mo...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.181.7.2124-2131.1999
更新日期:1999-04-01 00:00:00
abstract::Agrobacterium tumefaciens transfers single-stranded DNAs (T strands) into plant cells. VirE1 and VirE2, which is a single-stranded DNA binding protein, are important for tumorigenesis. We show that T strands and VirE2 can enter plant cells independently and that export of VirE2, but not of T strands, depends on VirE1....
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.178.4.1207-1212.1996
更新日期:1996-02-01 00:00:00
abstract::Three spontaneous derivatives of Streptococcus faecium ATCC 9790, originally isolated as conditionally Triton X-100 detergent-resistant at 25 degrees C, displayed normal penicillin-induced rates of lysis at 37 degrees C but substantially reduced rates of lysis and killing at 25 degrees C. The addition of exogenous uns...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.159.2.805-807.1984
更新日期:1984-08-01 00:00:00
abstract::We have examined the uptake of [14C]octopine and [14C]nopaline by Agrobacterium tumefaciens strains containing the C58 chromosomal background in medium suitable for the induction of vir genes. All strains tested could transport both of these opines, regardless of the presence or type of Ti plasmid (octopine or nopalin...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.173.2.903-905.1991
更新日期:1991-01-01 00:00:00
abstract::Ethanolamine (EA) metabolism is a trait associated with enteric pathogens, including enterohemorrhagic Escherichia coli O157:H7 (EHEC). EHEC causes severe bloody diarrhea and hemolytic uremic syndrome. EHEC encodes the ethanolamine utilization (eut) operon that allows EHEC to metabolize EA and gain a competitive advan...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00937-13
更新日期:2013-11-01 00:00:00
abstract::Small subunit rRNA sequences have been determined for 10 of the most clinically important pathogenic species of the yeast genus Candida (including Torulopsis [Candida] glabrata and Yarrowia [Candida] lipolytica) and for Hansenula polymorpha. Phylogenetic analyses of these sequences and those of Saccharomyces cerevisia...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.173.7.2250-2255.1991
更新日期:1991-04-01 00:00:00
abstract::The tprK gene of Treponema pallidum subsp. pallidum, the causative agent of venereal syphilis, belongs to a 12-member gene family and encodes a protein with a predicted cleavable signal sequence and predicted transmembrane domains. Except for the Nichols type strain, all rabbit-propagated isolates of T. pallidum exami...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.185.21.6262-6268.2003
更新日期:2003-11-01 00:00:00
abstract::Acinetobacter sp. strain JC1 DSM 3803, a carboxydobacterium, grown on methanol was found to show dihydroxyacetone synthase, dihydroxyacetone kinase, and ribulose 1,5-bisphosphate carboxylase, but no hydroxypyruvate reductase and very low hexulose 6-phosphate synthase, activities. The dihydroxyacetone synthase was foun...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.179.19.6041-6047.1997
更新日期:1997-10-01 00:00:00
abstract::Glycosylation is a common modulation of protein function in eukaryotes and is biologically important. However, in bacteria protein glycosylation is rare, and relatively few bacterial glycoproteins are known. In Escherichia coli only two glycoproteins have been described to date. Here we introduce a novel member to thi...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.188.5.1798-1807.2006
更新日期:2006-03-01 00:00:00
abstract::In Acinetobacter calcoaceticus the seven genes coding for the enzymes responsible for tryptophan synthesis map at three chromosomal locations. Two three-gene clusters, one (trpGDC) specifying the small subunit of anthranilate synthase, phosphoribosyl transferase, and indoleglycerol phosphate synthase and the other (tr...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.127.1.367-379.1976
更新日期:1976-07-01 00:00:00
abstract::The Saccharomyces cerevisiae HIS7 gene was cloned by its location immediately downstream of the previously isolated and characterized ARO4 gene. The two genes have the same orientation with a distance of only 416 bp between the two open reading frames. The yeast HIS7 gene represents the first isolated eukaryotic gene ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.175.17.5548-5558.1993
更新日期:1993-09-01 00:00:00
abstract::Clostridium perfringens causes gas gangrene and gastrointestinal (GI) diseases in humans. The most common cause of C. perfringens-associated food poisoning is the consumption of C. perfringens vegetative cells followed by sporulation and production of enterotoxin in the gut. Despite the importance of spore formation i...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.02152-12
更新日期:2013-06-01 00:00:00
abstract::Transducing frequencies of phage P22 lysates prepared from Salmonella typhimurium exponential cultures in minimal and nutrient broth media were compared. The assumption is that cells grown in a minimal medium will have one replication fork per replication unit, but cells in nutrient broth will have multiple replicatio...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.115.1.168-176.1973
更新日期:1973-07-01 00:00:00
abstract::Previously, we characterized a pathway necessary for the processing of NAD+ and for uptake of nicotinamide riboside (NR) in Haemophilus influenzae. Here we report on the role of NadR, which is essential for NAD+ utilization in this organism. Different NadR variants with a deleted ribonucleotide kinase domain or with a...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.187.13.4410-4420.2005
更新日期:2005-07-01 00:00:00
abstract::Two proteins that bind penicillin were observed in Escherichia coli infected with lambda phages 141, 142, 650, and 651 from the Kohara genomic library. These phages carry chromosomal DNA fragments that do not contain any known penicillin binding protein (PBP) genes, indicating that unrecognized gene products were exhi...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.179.19.6112-6121.1997
更新日期:1997-10-01 00:00:00