IDENTIFICATION AND SEQUENCE OF THE GENE ENCODING CYTOCHROME-C HEME LYASE IN THE YEAST SACCHAROMYCES-CEREVISIAE
IDENTIFICATION AND SEQUENCE OF THE GENE ENCODING CYTOCHROME-C HEME LYASE IN THE YEAST SACCHAROMYCES-CEREVISIAE
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DOI：
10.1002/j.1460-2075.1987.tb04744.x
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发表时间：
1987-01-01
期刊：
影响因子：
11.4
通讯作者：
SHERMAN, F
中科院分区：
文献类型：
--
作者：
DUMONT, ME;ERNST, JF;SHERMAN, F
线粒体细胞色素c含有一个血红素基团，通过硫醚键共价连接到蛋白质的两个半胱氨酸残基上。我们在这里证明了酵母的核基因CYC3编码细胞色素c血红素裂解酶（CCHL），这种酶催化血红素附着到细胞色素c上。与正常菌株的提取物相比，CYC3突变体的线粒体提取物缺乏CCHL活性，而携带多个CYC3基因拷贝的菌株则表现出高水平的活性。CYC3基因是用先前分离的含有PYK1基因的质粒对CYC3突变体进行功能性互补克隆的，PYK1基因与CYC3紧密相连。从CYC3基因片段的DNA序列中鉴定出一个编码269个氨基酸的开放阅读框，相应的转录物显示为。apprx。长度为0.9 KB。CCHL似乎是一个单一的多肽链，它特异性地作用于两种形式的细胞色素c，但不作用于细胞色素c1。
Mitochondrial cytochrome c contains a heme group covalently attached through thioether linkages to two cysteinyl residues of the protein. We demonstrate here that the nuclear gene, CYC3, in the yeast Saccharomyces cerevisiae, encodes cytochrome c heme lyase (CCHL), the enzyme catalyzing the attachment of heme to apocytochrome c. Mitochondrial extracts from cyc3- mutants are deficient in CCHL activity compared with extracts from normal strains, whereas strains carrying multiple copies of the CYC3 gene exhibit high levels of the activity. The CYC3 gene was cloned by functional complementation of a cyc3- mutant using a previously isolated plasmid containing the gene PYK1, which is tightly linked to CYC3. An open reading frame encoding a protein of 269 amino acids was identified from the DNA sequence of a fragment encompassing the CYC3 gene, and the corresponding transcript shown to be .apprx. 0.9 kb in length. CCHL appears to be a single polypeptide chain which acts specifically on the two forms of cytochrome c, but not on cytochrome c1.