title: A novel adaptation of aldolase regulates virulence in Streptococcus pyogenes.
abstract: Regulation of virulence factor expression is critical for pathogenic microorganisms that must sense and adapt to a dynamic host environment; yet, the signal transduction pathways that enable this process are generally poorly understood. Here, we identify LacD.1 as a global regulator of virulence factor expression in the versatile human pathogen, Streptococcus pyogenes. LacD.1 is derived from a class I tagatose-1,6-bisphosphate aldolase homologous to those involved in lactose and galactose metabolism in related prokaryotes. However, regulation of transcription by LacD.1 is not dependent on this enzymatic activity or the canonical catabolite repression pathway, but likely does require substrate recognition. Our results suggest that LacD.1 has been adapted as a metabolic sensor, and raise the possibility that regulation of gene expression by metabolic enzymes may be a novel mechanism by which Gram-positive bacteria, including S. pyogenes, coordinate multiple environmental cues, allowing essential transcription programs to be coupled with perceived nutritional status.
authors.affiliation: Department of Molecular Microbiology, Washington University School of Medicine, St Louis, MO 63110, USA.
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Loughman
authors.forename: Michael G
authors.initials: MG
authors.lastname: Caparon
mesh_terms: D000446:Aldehyde-Lyases / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D005098:Exotoxins / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D006863:Hydrogen-Ion Concentration; D009154:Mutation; D012097:Repressor Proteins / Q000378:metabolism; D015398:Signal Transduction; D012965:Sodium Chloride / Q000378:metabolism; D013297:Streptococcus pyogenes / Q000201:enzymology / Q000472:pathogenicity / Q000502:physiology*; D013379:Substrate Specificity; D014774:Virulence; D037521:Virulence Factors / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D005098:Exotoxins; D012097:Repressor Proteins; C098249:RopB protein, Rhizobium leguminosarum; D037521:Virulence Factors; C069286:catabolite control proteins, bacteria; C027951:erythrogenic toxin; D012965:Sodium Chloride; D000446:Aldehyde-Lyases; C023093:tagatose 1,6-diphosphate aldolase