Eisenberg M A, Star C
J Bacteriol. 1968 Oct;96(4):1291-7. doi: 10.1128/jb.96.4.1291-1297.1968.
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.
在大肠杆菌K-12生物素突变体的无细胞提取物中证实了由庚二酰辅酶A和L-丙氨酸酶促合成7-氧代-8-氨基壬酸（7-KAP），该突变体仅将7-KAP分泌到生长培养基中。这种生物素维生素类似物通过其色谱和电泳特性得以鉴定。当该生物体在生物素浓度大于0.2 ng/ml的条件下生长时，该酶（7-KAP合成酶）受到抑制。除了其他维生素类似物外，还分泌7-KAP的亲本菌株和其他突变组的成员也表现出合成酶活性。一个未能分泌7-KAP的突变组进一步细分为三组，其中一组缺乏合成酶活性。结合先前提出的生物素生物合成方案对这些结果进行了讨论，在该方案中，7-KAP的形成被认为是庚二酸进入生物素途径的切入点。
