Suh S J, Escalante-Semerena J C
Department of Bacteriology, University of Wisconsin-Madison 53706-1567.
Gene. 1993 Jul 15;129(1):93-7. doi: 10.1016/0378-1119(93)90701-4.
The cobA gene of Salmonella typhimurium was cloned, sequenced and overexpressed. A 990-bp HpaI-SacI fragment was cloned into the multiple cloning site of plasmid pSU19, an intermediate-copy-number vector. DNA sequence analysis established that cobA is 588 bp in length and codes for a protein with a predicted molecular weight of 21.7 kDa. However, the CobA protein expressed from the T7 promoter migrated as a 25-kDa protein on SDS-polyacrylamide gels. A high degree of identity at the amino acid sequence level was established between the CobA, Pseudomonas denitrificans CobO and Escherichia coli BtuR proteins. P. denitrificans CobO has been shown to be a ATP:corrinoid adenosyltransferase enzyme. Based on the similarities between CobO and CobA, and the phenotypes of cobA mutants, we suggest that CobA is the ATP:corrinoid adenosyltransferase of S. typhimurium.
鼠伤寒沙门氏菌的cobA基因被克隆、测序并过量表达。一个990 bp的HpaI - SacI片段被克隆到质粒pSU19（一种中等拷贝数载体）的多克隆位点中。DNA序列分析表明，cobA长度为588 bp，编码一种预测分子量为21.7 kDa的蛋白质。然而，从T7启动子表达的CobA蛋白在SDS - 聚丙烯酰胺凝胶上迁移为25 kDa的蛋白。在CobA、反硝化假单胞菌CobO和大肠杆菌BtuR蛋白之间在氨基酸序列水平上建立了高度的同一性。反硝化假单胞菌CobO已被证明是一种ATP：类咕啉腺苷转移酶。基于CobO和CobA之间的相似性以及cobA突变体的表型，我们认为CobA是鼠伤寒沙门氏菌的ATP：类咕啉腺苷转移酶。
