title: Availability of porphobilinogen controls appearance of porphobilinogen deaminase activity in Escherichia coli K-12.
abstract: A hemin-permeable hemB mutant had no 5-aminolevulinate dehydratase (ALA D) and extremely low porphobilinogen deaminase (PBG D) activity. When the structural gene for hemB was introduced into this strain on a single-copy plasmid, both activities were observed. When the mutant was grown on PBG, normal PBG D activity was observed. Moreover, a hemA mutant had little or no PBG D activity unless it was grown on ALA or PBG. Neither hemin nor PBG affected the level of PBG D protein produced from in vitro transcription and translation of a plasmid harboring the hemC gene as an insert. We conclude that, in Escherichia coli, PBG availability controls the activity of PBG D at some posttranscriptional level.
mesh_terms: D000622:Aminolevulinic Acid / Q000378:metabolism; D000642:Ammonia-Lyases / Q000378:metabolism*; D004790:Enzyme Induction; D004926:Escherichia coli / Q000201:enzymology*; D006427:Hemin / Q000378:metabolism; D011163:Hydroxymethylbilane Synthase / Q000378:metabolism*; D011162:Porphobilinogen / Q000378:metabolism*
chemical_list: D006427:Hemin; D011162:Porphobilinogen; D000622:Aminolevulinic Acid; D011163:Hydroxymethylbilane Synthase; D000642:Ammonia-Lyases