Sidhu H, Ogden S D, Lung H Y, Luttge B G, Baetz A L, Peck A B
Program in Experimental Pathology, Department of Pathology and Laboratory Medicine, University of Florida College of Medicine, Gainesville 32610, USA.
J Bacteriol. 1997 May;179(10):3378-81. doi: 10.1128/jb.179.10.3378-3381.1997.
Oxalic acid, a highly toxic by-product of metabolism, is catabolized by a limited number of bacterial species utilizing an activation-decarboxylation reaction which yields formate and CO2. frc, the gene encoding formyl coenzyme A transferase, an enzyme which transfers a coenzyme A moiety to activate oxalic acid, was cloned from the bacterium Oxalobacter formigenes. DNA sequencing revealed a single open reading frame of 1,284 bp capable of encoding a 428-amino-acid protein. A presumed promoter region and a rho-independent termination sequence suggest that this gene is part of a monocistronic operon. A PCR fragment containing the open reading frame, when overexpressed in Escherichia coli, produced a product exhibiting enzymatic activity similar to the purified native enzyme. With this, the two genes necessary for bacterial catabolism of oxalate, frc and oxc, have now been cloned, sequenced, and expressed.
草酸是一种代谢产生的剧毒副产物，少数细菌物种通过利用一种产生甲酸盐和二氧化碳的激活脱羧反应来分解代谢草酸。frc基因编码甲酰辅酶A转移酶，该酶可转移辅酶A部分以激活草酸，它是从产甲酸草酸杆菌中克隆得到的。DNA测序显示有一个1284 bp的单一开放阅读框，能够编码一个428个氨基酸的蛋白质。一个推测的启动子区域和一个不依赖于rho因子的终止序列表明该基因是一个单顺反子操纵子的一部分。当在大肠杆菌中过表达时，一个包含开放阅读框的PCR片段产生了一种具有与纯化的天然酶相似酶活性的产物。至此，草酸细菌分解代谢所需的两个基因frc和oxc已被克隆、测序并表达。
