Regulation of the heme A biosynthetic pathway in Saccharomyces cerevisiae
Regulation of the heme A biosynthetic pathway in Saccharomyces cerevisiae
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DOI：
10.1016/s0014-5793(02)02514-0
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发表时间：
2002-04-10
期刊：
影响因子：
3.5
通讯作者：
Tzagoloff, A
中科院分区：
文献类型：
--
作者：
Barros, MH;Tzagoloff, A
血红素A是细胞色素氧化酶（考克斯）的辅基，其生物合成涉及血红素B的初始法尼基化.在该反应中形成的血红素0产物通过卟啉环的碳C-8处的甲基的羟基化来改性。该反应被认为是由Cox 15 p、铁氧还蛋白和铁氧还蛋白还原酶催化的。醇氧化成相应的醛产生血红素A。在本研究中，我们测定了酵母考克斯突变体中的血红素A和血红素0。稳态浓度的两个血红素在不同的菌株研究表明，羟基化血红素0，催化的Cox 15 p，调节由一个亚基或组装中间体的考克斯。突变体的血红素配置文件也表明正调控血红素B法尼基化的羟基化中间体形成在随后的步骤或Cox 15 p本身。(C)2002年由Elsevier Science B. V.代表欧洲生物化学学会联合会出版。
Biosynthesis of heme A, a prosthetic group of cytochrome oxidase (COX), involves an initial farnesylation of heme B. The heme 0 product formed in this reaction is modified by hydroxylation of the methyl group at carbon C-8 of the porphyrin ring. This reaction was proposed to be catalyzed by Cox15p, ferredoxin, and ferredoxin reductase. Oxidation of the alcohol to the corresponding aldehyde yields heme A. In the present study we have assayed heme A and heme 0 in yeast COX mutants. The steady state concentrations of the two hemes in the different strains studied indicate that hydroxylation of heme 0, catalyzed by Cox15p, is regulated either by a subunit or assembly intermediate of COX. The heme profiles of the mutants also suggest positive regulation of heme B farnesylation by the hydroxylated intermediate formed at the subsequent step or by Cox15p itself. (C) 2002 Published by Elsevier Science B.V. on behalf of the Federation of European Biochemical Societies.