title: Autoregulation: a role for a biosynthetic enzyme in the control of gene expression.
abstract: It was previously proposed, primarily on the basis of evidence in vitro, that L-threonine deaminase, the ilvA gene product, is required for repression of its own synthesis and for repression of the other genes in the ilv-ADE operon. In this communication, evidence in vivo is presented that supports this autoregulatory model. Further evidence is presented that suggests that L-threonine deaminase is also required for induction of the ilvC gene product. The autoregulatory model is presented in an expanded form to include recent evidence that L-threonine deaminase (EC 4.2.1.16) is a central element for repression of the ilvADE and ilvB operons, and for induction of the ilvC operon.
mesh_terms: D004790:Enzyme Induction; D004794:Enzyme Repression; D005246:Feedback; D005796:Genes; D006836:Hydro-Lyases / Q000096:biosynthesis / Q000378:metabolism*; D006885:Hydroxybutyrates; D007532:Isoleucine / Q000096:biosynthesis / Q000378:metabolism; D007535:Isomerases / Q000096:biosynthesis; D007773:Lactates; D007930:Leucine / Q000378:metabolism; D008967:Molecular Biology; D009876:Operon; D012486:Salmonella typhimurium / Q000201:enzymology*; D013912:Threonine; D014633:Valine / Q000096:biosynthesis / Q000378:metabolism
chemical_list: D006885:Hydroxybutyrates; D007773:Lactates; D007532:Isoleucine; D013912:Threonine; D006836:Hydro-Lyases; D007535:Isomerases; D007930:Leucine; D014633:Valine