期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1971
卷号：68
期号：6
页码：1259-1263
DOI：10.1073/pnas.68.6.1259
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Acetyl CoA carboxylase of Escherichia coli has been resolved into three functionally dissimilar proteins: (1) biotin-carboxyl carrier protein (BCCP); (2) a biotin carboxylase component that catalyzes the Mn-ATP-dependent carboxylation of BCCP to form CO2--BCCP; and (3) a transcarboxylase component that catalyzes the transfer of the carboxyl group from CO2--BCCP to acetyl CoA to form malonyl CoA. The transcarboxylase has been purified 1700-fold. Evidence that this protein catalyzes the transcarboxylase step includes the demonstration that it (a) catalyzes the carboxylation of BCCP, (b) catalyzes the BCCP-dependent exchange between [14C]acetyl CoA and malonyl CoA, (c) binds labeled acetyl CoA and malonyl CoA, and (d) catalyzes the decarboxylation of CO2--BCCP. On the basis of this evidence, it is concluded that the transcarboxylase component contains sites for the acyl CoA group and for biotin, the covalently bound prosthetic group of BCCP.
关键词：acyl CoA binding ; carboxylation ; exchange reactions ; biotin
