Abstract:
:Lactose is an abundant dietary carbohydrate metabolized by the dental pathogen Streptococcus mutans. Lactose metabolism presents both classic diauxic behaviors and long-term memory, where the bacteria can pause for >11 h before initiating growth on lactose. Here, we explored mechanisms contributing to unusual aspects of regulation of the lac operon. The fructose-phosphate metabolites, F-1-P and F-6-P, could modulate the DNA-binding activities of the lactose repressor. Recombinant LacR proteins bound upstream of lacA and Gal-6-P induced the formation of different LacR-DNA complexes. Deletion of lacR resulted in strain-specific growth phenotypes on lactose, but also on a number of mono- and di-saccharides that involve the glucose-PTS or glucokinase in their catabolism. The phenotypes were consistent with the novel findings that loss of LacR altered glucose-PTS activity and expression of the gene for glucokinase. CcpA was also shown to affect lactose metabolism in vivo and to bind to the lacA promoter region in vitro. Collectively, our study reveals complex molecular circuits controlling lactose metabolism in S. mutans, where LacR and CcpA integrate cellular and environmental cues to regulate metabolism of a variety of carbohydrates that are critical to persistence and pathogenicity of S. mutans.
journal_name
Mol Microbioljournal_title
Molecular microbiologyauthors
Zeng L,Burne RAdoi
10.1111/mmi.14597subject
Has Abstractpub_date
2020-09-03 00:00:00eissn
0950-382Xissn
1365-2958pub_type
杂志文章abstract::A locust within chromosome XIII of Saccharomyces cerevisiae containing four genes upregulated by osmotic stress has been characterized. Two of the genes, but not their osmotic induction, were already described: the DNA damage-inducible gene DDR48 and the protease inhibitor gene PAI3. The two novel genes encode a cytop...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.1995.mmi_17040653.x
更新日期:1995-08-01 00:00:00
abstract::A 1.3 kb cDNA (cDNA52) was derived from Trypanosoma cruzi trypomastigote mRNA. Using single stranded probes in Northern blots, we identified the putative coding strand of cDNA52. In addition, a minor band was detected in RNA from epimastigotes that was absent in RNA from trypomastigotes. Nucleotide sequence analysis r...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.1991.tb01841.x
更新日期:1991-01-01 00:00:00
abstract::Osmoregulatory mutants of Saccharomyces cerevisiae with a defect in their capacity to readjust the cell volume/buoyant density after osmotically induced dehydration were enriched by density gradient centrifugation. Colonies derived from cells that remained dense after dehydration were screened for sensitivity to high ...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.1993.tb00980.x
更新日期:1993-12-01 00:00:00
abstract::Eeyarestatin 1 (ES1) is an inhibitor of endoplasmic reticulum (ER) associated protein degradation, Sec61-dependent Ca2+ homeostasis and protein translocation into the ER. Recently, evidence was presented showing that a smaller analog of ES1, ES24, targets the Sec61-translocon, and captures it in an open conformation t...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/mmi.14589
更新日期:2020-08-15 00:00:00
abstract::Pseudomonas fluorescens ATCC 17400 produces pyoverdine under iron-limiting conditions. A Tn5 mutant, 2G11, produced lower amounts of different pyoverdine forms and was unable to grow under iron limitation caused by ethylenediamine-di(o-hydroxy-phenylacetic acid) (EDDHA) or zinc. This mutant was complemented by a 9.6 k...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1046/j.1365-2958.1996.391399.x
更新日期:1996-08-01 00:00:00
abstract::The ability of a bacterial pathogen to monitor available carbon sources in host tissues provides a clear fitness advantage. In the group A streptococcus (GAS), the virulence regulator Mga contains homology to phosphotransferase system (PTS) regulatory domains (PRDs) found in sugar operon regulators. Here we show that ...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/mmi.12250
更新日期:2013-06-01 00:00:00
abstract::In cyanobacteria and chloroplasts, exposure to HL damages the photosynthetic apparatus, especially the D1 subunit of Photosystem II. To avoid chronic photoinhibition, a PSII repair cycle operates to replace damaged PSII subunits with newly synthesised versions. To determine the sub-cellular location of this process, w...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/mmi.12940
更新日期:2015-05-01 00:00:00
abstract::Neisseria gonorrhoeae homologues of gyrA and parC have been identified using hybridization probes generated from conserved regions of diverse gyrA genes. These genes have been tentatively identified as gyrA and parC, based on predicted amino acid sequence homologies to known GyrA homologues from numerous bacterial spe...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.1994.tb01297.x
更新日期:1994-10-01 00:00:00
abstract::The fibronectin binding protein, FnBPA, is a multifunctional microbial surface component recognizing adhesive matrix molecule (MSCRAMM) that promotes bacterial adherence to immobilized fibrinogen and elastin via the N-terminal A domain. The binding site for fibrinogen and elastin was localized to subdomains N2N3. A th...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2006.05552.x
更新日期:2007-02-01 00:00:00
abstract::Mutation of staphylococcal accessory regulator (sarA) results in increased production of extracellular proteases in Staphylococcus aureus, which has been correlated with decreased biofilm formation and decreased accumulation of extracellular toxins. We used murine models of implant-associated biofilm infection and S. ...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/mmi.12048
更新日期:2012-12-01 00:00:00
abstract::In the past, ultrastructural investigations of Leishmania mexicana amastigotes revealed structures that were tentatively identified as autophagosomes. This study has now provided definitive data that autophagy occurs in the parasite during differentiation both to metacyclic promastigotes and to amastigotes, autophagos...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2006.05274.x
更新日期:2006-08-01 00:00:00
abstract::Holins control the length of the infection cycle of tailed phages (the Caudovirales) by oligomerizing to form lethal holes in the cytoplasmic membrane at a time dictated by their primary structure. Nothing is currently known about the physical basis of their oligomerization or the structure of the oligomers formed by ...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2008.06298.x
更新日期:2008-08-01 00:00:00
abstract::The bacterial RNA-binding protein Hfq functions in post-transcriptional regulation of gene expression. There is evidence in a range of bacteria for specific subcellular localization of Hfq; however, the mechanism and role of Hfq localization remain unclear. Cyanobacteria harbour a subfamily of Hfq that is structurally...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/mmi.12595
更新日期:2014-05-01 00:00:00
abstract::Bacterial chemoreceptors cluster into exquisitively sensitive, tunable, highly ordered, polar arrays. While these arrays serve as paradigms of cell signalling in general, it remains unclear what conformational changes transduce signals from the periplasmic tips, where attractants and repellents bind, to the cytoplasmi...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2011.07854.x
更新日期:2011-11-01 00:00:00
abstract::Cell cycle transitions are often triggered by the proteolysis of key regulatory proteins. In Caulobacter crescentus, the G1-S transition involves the degradation of an essential DNA-binding response regulator, CtrA, by the ClpXP protease. Here, we show that another critical cell cycle regulator, SciP, is also degraded...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/mmi.12166
更新日期:2013-03-01 00:00:00
abstract::Virulence factors secreted by Listeria monocytogenes are known to interfere with host cellular signalling pathways. We investigated whether L. monocytogenes modulates T-cell receptor signalling by examining surface expression of proteins known to be upregulated on activated T cells. In vitro culture of murine splenocy...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2003.03931.x
更新日期:2004-03-01 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::Bacterial autotransporters consist of an N-terminal 'passenger domain' that is transported into the extracellular space by an unknown mechanism and a C-terminal 'beta-domain' that forms a beta-barrel in the outer membrane. Recent studies have revealed that fully assembled autotransporters have an unusual architecture ...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2007.06048.x
更新日期:2008-01-01 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
abstract::Motile bacteria sense their physical and chemical environment through highly cooperative, ordered arrays of chemoreceptors. These signalling complexes phosphorylate a response regulator which in turn governs flagellar motor reversals, driving cells towards favourable environments. The structural changes that translate...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/mmi.12309
更新日期:2013-09-01 00:00:00
abstract::The surface of Trypanosoma brucei is covered by a dense coat of glycosylphosphatidylinositol-anchored glycoproteins. The major component is the variant surface glycoprotein (VSG) which is glycosylated by both paucimannose and oligomannose N-glycans. Surface glycans are poorly accessible and killing mediated by peptide...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/mmi.12359
更新日期:2013-11-01 00:00:00
abstract::We have investigated the possible role of Escherichia coli DNA polymerase (Pol) I in chromosomal replication fidelity. This was done by substituting the chromosomal polA gene by the polAexo variant containing an inactivated 3'-->5' exonuclease, which serves as a proofreader for this enzyme's misinsertion errors. Using...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2009.06921.x
更新日期:2009-12-01 00:00:00
abstract::We present evidence showing that rpoS (katF) is a regulator of katG gene transcription in an oxyR-independent manner. Mutation of the rpoS gene in several different Escherichia coli strains caused a significant reduction in catalase HPI activity. In rpoS-delta oxyR double mutants, the level of HPI was considerably low...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.1994.tb01043.x
更新日期:1994-05-01 00:00:00
abstract::The chaperone/usher (CU) pathway is a conserved bacterial secretion system that assembles adhesive fibres termed pili or fimbriae. Pilus biogenesis by the CU pathway requires a periplasmic chaperone and an outer membrane (OM) assembly platform termed the usher. The usher catalyses formation of subunit-subunit interact...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2010.07505.x
更新日期:2011-02-01 00:00:00
abstract::The bvg locus contains two genes, bvgA and bvgS, which control the expression of the virulence-associated genes in Bordetella species by a system similar to the two-component systems used by a variety of bacterial species to respond to environmental stimuli. We determined the nucleotide sequence of the bvg loci of Bor...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.1991.tb02093.x
更新日期:1991-10-01 00:00:00
abstract::We cloned the CaYFH1 gene that encodes the yeast frataxin homologue in Candida albicans. CaYFH1 was expressed in Deltayfh1 Saccharomyces cerevisiae cells, where it compensated for all the phenotypes tested except for the lack of cytochromes. Double DeltaCayfh1/DeltaCayfh1 mutant had severe defective growth, accumulate...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2004.04281.x
更新日期:2004-10-01 00:00:00
abstract::clpC of Bacillus subtilis is part of an operon containing six genes. Northern blot analysis suggested that all genes are co-transcribed and encode stress-inducible proteins. Two promoters (PA and PB) were mapped upstream of the first gene. PA resembles promoters recognized by the vegetative RNA polymerase E sigma A. T...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.1996.tb02511.x
更新日期:1996-05-01 00:00:00
abstract::Of the four Plasmodium species that routinely cause malaria in humans, Plasmodium falciparum is responsible for the majority of malaria mortality and consequently gets most of the headlines. Outside Africa, however, more malaria cases are caused by its distant cousin Plasmodium vivax, resulting in a daunting morbidity...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2005.04518.x
更新日期:2005-03-01 00:00:00
abstract::CTXphi is a filamentous phage that encodes cholera toxin, one of the principal virulence factors of Vibrio cholerae. CTXphi is unusual among filamentous phages because it can either replicate as a plasmid or integrate into the V. cholerae chromosome at a specific site. The CTXphi genome has two regions, the 'core' and...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1046/j.1365-2958.1997.3911758.x
更新日期:1997-06-01 00:00:00
abstract::Rpc25 is a strongly conserved subunit of RNA polymerase III with homology to Rpa43 in RNA polymerase I, Rpb7 in RNA polymerase II and the archaeal RpoE subunit. A central domain of Rpc25 can replaced the corresponding region of Rpb7 with little or no growth defect, underscoring the functional relatedness of these prot...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2004.04375.x
更新日期:2005-01-01 00:00:00