Yamamoto Y, Miwa Y, Miyoshi K, Furuyama J, Ohmori H
Department of Genetics, Hyogo College of Medicine, Japan.
Genes Genet Syst. 1997 Jun;72(3):167-72. doi: 10.1266/ggs.72.167.
A gene (designated ldcC) mapped at 4.6 min on the Escherichia coli chromosome codes for a protein of 713 amino acids (aa) that shows strong similarities in both size and amino-acid sequence (69% identical residues and 85% conserved residues) to lysine decarboxylase (LDC) from E. coli (CadA, acid-inducible LDC, 715 aa) or from Hafnia alvei (739 aa). A pUC18 derivative carrying the ldcC gene conferred high LDC activities on an E. coli strain devoid of the functional cadA gene, even when the bacteria were grown under non-inducing conditions at physiological pH. Thus, the gene encodes another lysine decarboxylase, probably a constitutively expressed enzyme, the presence of which was suggested from the previous observations that low LDC activities were detectable in cadA- mutant and non-induced wild-type cells.
一个定位在大肠杆菌染色体4.6分钟处的基因（命名为ldcC）编码一种由713个氨基酸组成的蛋白质，该蛋白质在大小和氨基酸序列上与来自大肠杆菌（CadA，酸诱导型赖氨酸脱羧酶，715个氨基酸）或蜂房哈夫尼亚菌（739个氨基酸）的赖氨酸脱羧酶（LDC）具有很强的相似性（69%的相同残基和85%的保守残基）。携带ldcC基因的pUC18衍生物赋予了缺乏功能性cadA基因的大肠杆菌菌株高LDC活性，即使细菌在生理pH值的非诱导条件下生长也是如此。因此，该基因编码另一种赖氨酸脱羧酶，可能是一种组成型表达的酶，根据之前的观察结果推测其存在，即在cadA突变体和未诱导的野生型细胞中可检测到低LDC活性。
