title: Phosphotransbutyrylase expression in Bacillus megaterium.
abstract: The molecular analysis of a genomic region of B. megaterium revealed the presence of a gene coding for the enzyme phosphotransbutyrylase (Ptb). The enzyme activity was measured throughout the different phases of growth in B. megaterium, and its activity was found to be maximal in the late exponential growth phase. The branched amino acids isoleucine and valine activated Ptb expression. PtbBm was capable of using butyryl-CoA and 2-methyl-propionyl CoA as substrates. ActBm, a final sigma54 regulator from B. megaterium whose gene is situated upstream from the ptb gene, activated its expression.
authors.affiliation: Departamento de Química Biológica, Ciudad Universitaria Pabellón 2, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, 1428 Buenos Aires, Argentina.
authors.forename: G J
authors.initials: GJ
authors.lastname: Vazquez
authors.forename: M J
authors.initials: MJ
authors.lastname: Pettinari
authors.forename: B S
authors.initials: BS
authors.lastname: Méndez
mesh_terms: D000597:Amino Acids, Branched-Chain / Q000494:pharmacology; D001410:Bacillus megaterium / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development*; D003470:Culture Media / Q000737:chemistry; D004268:DNA-Binding Proteins; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D007700:Kinetics; D010709:Phosphate Acetyltransferase / Q000235:genetics* / Q000378:metabolism*; D051877:RNA Polymerase Sigma 54; D012808:Sigma Factor / Q000378:metabolism
chemical_list: D000597:Amino Acids, Branched-Chain; D003470:Culture Media; D004268:DNA-Binding Proteins; D012808:Sigma Factor; D010709:Phosphate Acetyltransferase; D012321:DNA-Directed RNA Polymerases; D051877:RNA Polymerase Sigma 54