Abstract:
:The majority of characterized bacterial dipeptide permeases (Dpp) are membrane-associated complexes of five proteins belonging to the ABC-transporter family. They have been found to be involved in the uptake of essential amino acids, haem production, chemotaxis and sporulation. A 5.8 kb genomic DNA fragment of the serotype M49 group A streptococcal (GAS) strain CS101 was sequenced and found to contain five putative GAS Dpp genes (dppA to dppE). Deduced amino acid sequences exhibited 17-54% similarity to corresponding ABC-transporter sequences. The operon organization of the five genes was confirmed by transcriptional analysis, and a shorter, more abundant, dppA-only transcript was detected similar to that found in the GAS oligopeptide permease (Opp) system. Insertional inactivation was used to create serotype M2 and M49 strains that did not express the dppD and dppEATPase genes or nearly the entire operon. In feeding experiments with di- to hexapeptides, the wild-type strain grew with each peptide tested. The dpp mutants were unable to grow on dipeptides, whereas hexapeptides did not sustain the growth of opp mutants. Expression of the dpp operon was induced approximately fourfold in late exponential growth phase. In addition, a striking increase in the dppA to dppA-E ratio from 5:1 to more than 20:1 occurred during late exponential growth phase in complex medium. Growth in chemically defined medium (CDM) supplemented with various dipeptides specifically induced the expression of dpp and reduced both the dppA to dppA-E and oppA to oppA-F mRNA ratios. Expression of the virulence factor SpeB (major cysteine protease) was reduced eightfold in dpp mutants, whereas dpp expression was decreased about fourfold in a Mga virulence regulator mutant. Taken together, these data indicate a correlation between levels of intracellular essential amino acids and the regulation of virulence factor expression.
journal_name
Mol Microbioljournal_title
Molecular microbiologyauthors
Podbielski A,Leonard BAdoi
10.1046/j.1365-2958.1998.00898.xsubject
Has Abstractpub_date
1998-06-01 00:00:00pages
1323-34issue
6eissn
0950-382Xissn
1365-2958journal_volume
28pub_type
杂志文章abstract::The regulation of gene expression by the two-component regulatory system PhoP/PhoQ is necessary for Salmonella typhimurium survival within macrophages, defensin resistance, acid resistance, and murine typhoid fever pathogenesis. Salmonella experience multiple environments during mammalian infection and survival requir...
journal_title:Molecular microbiology
pub_type: 杂志文章,评审
doi:10.1111/j.1365-2958.1991.tb02135.x
更新日期:1991-09-01 00:00:00
abstract::We have examined the role of the F-plasmid TraV outer membrane lipoprotein in the assembly of F-pili. Yeast two-hybrid analysis with a traV bait repeatedly identified traK, which is predicted to encode a periplasmic protein, among positive prey plasmids. A traK bait in turn identified traV and traB, which is predicted...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1046/j.1365-2958.2001.02667.x
更新日期:2001-11-01 00:00:00
abstract::The outer membrane channel TolC is a key component of multidrug efflux and type I secretion transporters in Escherichia coli. Mutational inactivation of TolC renders cells highly susceptible to antibiotics and leads to defects in secretion of protein toxins. Despite impairment of various transport functions, no growth...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2010.07245.x
更新日期:2010-08-01 00:00:00
abstract::Gram-negative bacteria possess several envelope stress responses that detect and respond to damage to this critical cellular compartment. The σ(E) envelope stress response senses the misfolding of outer membrane proteins (OMPs), while the Cpx two-component system is believed to detect the misfolding of periplasmic and...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/mmi.12581
更新日期:2014-05-01 00:00:00
abstract::The ubiquitous human commensal Escherichia coli has been well investigated through its model representative E. coli K-12. In this work, we initially characterized E. coli Fec10, a recently isolated human commensal strain of phylogroup A/sequence type ST10. Compared to E. coli K-12, the 4.88 Mbp Fec10 genome is charact...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/mmi.14614
更新日期:2020-09-28 00:00:00
abstract::A 2.7 kb fragment of Helicobacter pylori UA802 chromosomal DNA was cloned and sequenced. Three open reading frames (designated ORF1, ORF2 and ORF3, respectively) were predicted from the DNA sequence, of which ORF1 and ORF2 appeared to be located within the same operon. The deduced 611-amino-acid sequence of ORF1, a P-...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.1995.tb02224.x
更新日期:1995-01-01 00:00:00
abstract::Candida albicans hyphae grow in a highly polarized fashion from their tips. This polarized growth requires the continuous delivery of secretory vesicles to the tip region. Vesicle delivery depends on Sec2p, the Guanine Exchange Factor (GEF) for the Rab GTPase Sec4p. GTP bound Sec4p is required for the transit of secre...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/mmi.12799
更新日期:2014-11-01 00:00:00
abstract::Transcriptional regulation is the key to ensuring that proteins are expressed at the proper time and the proper amount. In Escherichia coli, the transcription factor cAMP receptor protein (CRP) is responsible for much of this regulation. Questions remain, however, regarding the regulation of CRP activity itself. Here,...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/mmi.13874
更新日期:2018-01-01 00:00:00
abstract::The production of the bacterial DNA replication inhibitor Microcin B17 is induced as cultures enter stationary phase. Using S1 nuclease protection assays we have shown that this induction is the result of increased levels of transcription initiation from a promoter located upstream from mcbA, the structural gene for M...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.1987.tb00512.x
更新日期:1987-09-01 00:00:00
abstract::The mechanistic details of the pathogenesis of Chlamydia, an obligate intracellular pathogen of global importance, have eluded scientists due to the scarcity of traditional molecular genetic tools to investigate this organism. Here we report a chemical biology strategy that has uncovered the first essential protease f...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/mmi.12306
更新日期:2013-08-01 00:00:00
abstract::Expression of the cysteine regulon in Salmonella typhimurium and Escherichia coli is controlled by the LysR-type transcriptional activator CysB and by the inducer N-acetyl-L-serine. Sulphide and thiosulphate are anti-inducers. Two highly purified constitutive CysB proteins, CysB(T149M) and CysB(T149P), were found to b...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1046/j.1365-2958.1996.6301347.x
更新日期:1996-07-01 00:00:00
abstract::One often compares cells to computers, and signalling proteins to transistors. Location and wiring of those molecular transistors is paramount in defining the function of the subcellular chips. The bacterial chemotactic sensing apparatus is a large, stable assembly consisting of thousands of receptors, signal transduc...
journal_title:Molecular microbiology
pub_type: 评论,杂志文章
doi:10.1111/j.1365-2958.2008.06240.x
更新日期:2008-07-01 00:00:00
abstract::Renewed interest in gene amplification stems from its importance in evolution and a variety of medical problems ranging from drug resistance to cancer. However, amplified DNA segments (amplicons) are not fully characterized in any organism. Here we report a novel Acinetobacter baylyi system for genome-wide studies. Am...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2011.07945.x
更新日期:2012-02-01 00:00:00
abstract::Monoclonal antibodies against the lipopolysaccharide (LPS) of the deep rough mutant I-69 Rd-/b+ of Haemophilus influenzae were obtained after immunization of mice with sheep erythrocytes which had been coated with de-O-acylated LPS. Characterization of antibodies was performed by enzyme immuno assay (EIA) using LPS or...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1046/j.1365-2958.1997.d01-1877.x
更新日期:1997-02-01 00:00:00
abstract::The bacterial flagellum contains a specialized secretion apparatus in its base that pumps certain protein subunits through the growing structure to their sites of installation beyond the membrane. A related apparatus functions in the injectisomes of gram-negative pathogens to export virulence factors into host cells. ...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/mmi.13623
更新日期:2017-04-01 00:00:00
abstract::Arsenic is the most ubiquitous environmental toxin. Here, we demonstrate that bacteria have evolved the ability to use arsenic to gain a competitive advantage over other bacteria at least twice. Microbes generate toxic methylarsenite (MAs(III)) by methylation of arsenite (As(III)) or reduction of methylarsenate (MAs(V...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/mmi.14169
更新日期:2019-02-01 00:00:00
abstract::Colonies of strains carrying a stable lambdaplacMu15 translational fusion displayed sharply defined intense staining at the centre on Xgal medium. The fusion was in fiu (ferric ion uptake), encoding an iron-regulated outer membrane protein (IROMP) controlled via four overlapping ferric uptake regulator (Fur) boxes in ...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1046/j.1365-2958.1999.01423.x
更新日期:1999-07-01 00:00:00
abstract::SpsA, a pneumococcal surface protein belonging to the family of choline-binding proteins, interacts specifically with secretory immunglobulin A (SIgA) via the secretory component (SC). SIgA and free SC from mouse, rat, rabbit and guinea-pig failed to interact with SpsA indicating species-specific binding to human SIgA...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1046/j.1365-2958.2000.01897.x
更新日期:2000-05-01 00:00:00
abstract::Streptomyces lividans has a novel DNA modification, which sensitises its DNA to degradation during electrophoresis (the Dnd phenotype). The entire gene cluster (dnd) involved in this modification was localized on an 8 kb DNA fragment and was expressed in a S. lividans deletion mutant (dnd) and in several heterologous ...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2005.04764.x
更新日期:2005-09-01 00:00:00
abstract::Ler, encoded by the locus of enterocyte effacement (LEE) of attaching and effacing (A/E) pathogens, induces the expression of LEE genes by counteracting the silencing exerted by H-NS. Ler expression is modulated by several global regulators, and is activated by GrlA, which is also LEE-encoded. Typical enteropathogenic...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2011.07819.x
更新日期:2011-10-01 00:00:00
abstract::Proteins with LytM (Peptidase_M23) domains are broadly distributed in bacteria and have been implicated in a variety of important processes, including cell division and cell-shape determination. Most LytM-like proteins that have been structurally and/or biochemically characterized are metallo-endopeptidases that cleav...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/mmi.12304
更新日期:2013-08-01 00:00:00
abstract::Numerous eukaryotes have developed specific metabolic traits that are not present in extensively studied model organisms. For instance, the procyclic insect form of Trypanosoma brucei, a parasite responsible for sleeping sickness in its mammalian-specific bloodstream form, metabolizes glucose into excreted succinate a...
journal_title:Molecular microbiology
pub_type: 杂志文章,评审
doi:10.1111/mmi.12990
更新日期:2015-06-01 00:00:00
abstract::Genotoxic agents from endogenous and exogenous sources cause double-strand breaks (DSBs) in chromosomal DNA. Given the threat these lesions pose to viability, it is not surprising that multiple, conserved mechanisms exist for their detection, processing and repair. Previous studies have established both functional non...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2010.07462.x
更新日期:2011-01-01 00:00:00
abstract::Infections with the azole-refractory yeast Candida glabrata are now commonly treated with the echinocandins caspofungin (CSF) or micafungin (MCF). True resistance (> 32-fold decreased susceptibility) to these lipopeptide inhibitors of cell wall synthesis is rare and strictly associated with mutations in integral memb...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2012.08194.x
更新日期:2012-10-01 00:00:00
abstract::Type III secretion systems are found in many Gram-negative bacteria. They are activated by contact with eukaryotic cells and inject virulence proteins inside them. Host cell detection requires a protein complex located at the tip of the device's external injection needle. The Shigella tip complex (TC) is composed of I...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/mmi.12843
更新日期:2015-01-01 00:00:00
abstract::In response to nitrate availability, Escherichia coli regulates the synthesis of a number of enzymes involved in anaerobic respiration and fermentation. When nitrate is present, nitrate reductase (narGHJI) gene expression is induced, while expression of the DMSO/TMAO reductase (dmsABC), fumarate reductase (frdABCD) an...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.1992.tb01364.x
更新日期:1992-07-01 00:00:00
abstract::Exposure of bacterial cells to temperature changes induces the synthesis of a set proteins. We investigated the control of expression of the cspA gene, coding for the major cold-shock protein of Escherichia coli. This protein was shown to be transiently induced upon shift to low temperature. We demonstrated that the c...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1046/j.1365-2958.1996.363898.x
更新日期:1996-01-01 00:00:00
abstract::Alternaria brassicicola is an important, necrotrophic fungal pathogen that causes black spot disease on Brassicas. In order to study pathogenicity mechanisms, gene deletion mutants were generated for 21 putative regulatory genes including kinases and transcription factors subjectively selected from the annotated A. br...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2009.06689.x
更新日期:2009-06-01 00:00:00
abstract::Listeria monocytogenes grows in the cytosol of mammalian cells and spreads from cell to cell without exiting the intracellular milieu. During cell-cell spread, bacteria become transiently entrapped in double-membrane vacuoles. Escape from these vacuoles is mediated in part by a bacterial phospholipase C (PC-PLC), whos...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1046/j.1365-2958.2000.01708.x
更新日期:2000-01-01 00:00:00
abstract::A model for the topology of the PhoE porin has been proposed according to which the polypeptide traverses the outer membrane sixteen times mostly as amphipathic beta-sheets, thereby exposing eight loops at the cell surface. Until now, no evidence has been obtained for the surface exposure of the third loop. Recently, ...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.1993.tb01104.x
更新日期:1993-01-01 00:00:00