title: Methionine biosynthesis in Agrobacterium tumefaciens: study of the first enzyme.
abstract: Here we characterize the first step in methionine biosynthesis in Agrobacterium tumefaciens, an α-proteobacterium. We explored the metA gene and its products and found several unique properties. Although the gene was annotated as a homoserine transsuccinylase, based upon sequence similarity to characterized homologs in other bacteria, including Escherichia coli, the enzyme uses acetyl-CoA as a substrate and therefore is functionally a transacetylase. Moreover, the protein is thermolabile and the gene is under regulation of heat shock transcriptional activator σ32. 3. The gene has a SAM-riboswitch, which shuts off transcription by σ-32 as well as by the vegetative σ-70.
authors.affiliation: Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv 69978, Israel. orotem82@walla.co.il
authors.forename: Or
authors.initials: O
authors.lastname: Rotem
authors.forename: Dvora
authors.initials: D
authors.lastname: Biran
authors.forename: Eliora Z
authors.initials: EZ
authors.lastname: Ron
mesh_terms: D016960:Agrobacterium tumefaciens / Q000201:enzymology* / Q000235:genetics; D000595:Amino Acid Sequence; D004795:Enzyme Stability; D015964:Gene Expression Regulation, Bacterial; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D051082:Homoserine O-Succinyltransferase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008715:Methionine / Q000096:biosynthesis*; D008969:Molecular Sequence Data; D058928:Riboswitch; D016415:Sequence Alignment; D013696:Temperature; D014158:Transcription, Genetic
chemical_list: D006360:Heat-Shock Proteins; D058928:Riboswitch; D008715:Methionine; D051082:Homoserine O-Succinyltransferase