Andrews E, Jansen R, Crane A M, Cholin S, McDonnell D, Ledley F D
Howard Hughes Medical Institute, Baylor College of Medicine, Houston, Texas 77030.
Biochem Med Metab Biol. 1993 Oct;50(2):135-44. doi: 10.1006/bmmb.1993.1055.
Methylmalonyl-CoA mutase is an adenosylcobalamin-dependent enzyme which catalyzes isomerization of methylmalonyl-CoA to succinyl-CoA. Previous reports have described cloning and sequencing of a cDNA for human methylmalonyl-CoA mutase. This clone does not express an active apoenzyme after gene transfer into primary MCM-deficient fibroblasts and contains several sequences which differ from the consensus sequence of other cDNA clones. We describe reconstruction of a functional MCM cDNA and expression of recombinant enzyme activity in primary fibroblasts and Saccharomyces cerevisiae. This consensus human MCM cDNA is capable of complementing the inherited defect in mut MMA and overexpressing an enzyme in yeast with kinetic properties indistinguishable from the enzyme in murine or human tissues.
甲基丙二酰辅酶A变位酶是一种依赖腺苷钴胺素的酶,它催化甲基丙二酰辅酶A异构化为琥珀酰辅酶A。先前的报道描述了人甲基丙二酰辅酶A变位酶cDNA的克隆和测序。该克隆在基因转移到原发性MCM缺陷成纤维细胞后不表达活性脱辅基酶,并且包含几个与其他cDNA克隆的共有序列不同的序列。我们描述了功能性MCM cDNA的重建以及重组酶活性在原发性成纤维细胞和酿酒酵母中的表达。这种共有序列的人MCM cDNA能够弥补mut MMA中的遗传缺陷,并在酵母中过表达一种酶,其动力学特性与小鼠或人体组织中的酶无法区分。