title: Synthesis of 7-oxo-8-aminopelargonic acid, a biotin vitamer, in cell-free extracts of Escherichia coli biotin auxotrophs.
abstract: The enzymatic synthesis of 7-oxo-8-aminopelargonic acid (7-KAP) from pimelyl-coenzyme A and l-alanine was demonstrated in cell-free extracts of a biotin mutant of Escherichia coli K-12 which excretes only 7-KAP into the growth medium. This biotin vitamer was identified by its chromatographic and electrophoretic properties. The enzyme (7-KAP synthetase) was repressed when the organism was grown in biotin concentrations greater than 0.2 ng/ml. The parent strain and members of other mutant groups that excrete 7-KAP, in addition to other vitamers, also exhibited synthetase activity. A mutant group that failed to excrete 7-KAP was further sub-divided into three groups, one of which lacked synthetase activity. These results are discussed in relation to a previously proposed scheme for biotin biosynthesis in which the formation of 7-KAP is considered the point of entry for pimelic acid into the biotin pathway.
mesh_terms: D000217:Acyltransferases; D000409:Alanine / Q000378:metabolism; D001710:Biotin / Q000032:analysis / Q000096:biosynthesis* / Q000494:pharmacology; D002474:Cell-Free System; D002854:Chromatography, Paper; D003065:Coenzyme A / Q000378:metabolism; D004586:Electrophoresis; D004794:Enzyme Repression; D004926:Escherichia coli / Q000378:metabolism*; D008190:Lyases / Q000378:metabolism
chemical_list: D001710:Biotin; D000217:Acyltransferases; C021929:8-amino-7-oxononanoate synthase; D008190:Lyases; D000409:Alanine; D003065:Coenzyme A