Structural characterization of Paracoccus denitrificans cytochrome c peroxidase and assignment of the low and high potential heme sites.
Structural characterization of Paracoccus denitrificans cytochrome c peroxidase and assignment of the low and high potential heme sites.
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脱氮副球菌细胞色素 c 过氧化物酶的结构表征以及低和高电位血红素位点的分配。
DOI：
10.1021/bi963131e
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发表时间：
1997
期刊：
影响因子：
2.9
通讯作者：
Jozef Van Beeumen
中科院分区：
文献类型：
--
作者：
Wei Hu;G. van Driessche;Bart Devreese;C. F. Goodhew;D. Mcginnity;Neil Saunders;Vilmos Fulop;G. Pettigrew;Jozef Van Beeumen
已确定的氨基酸序列的二血红素细胞色素c过氧化物酶从副球菌的apoprotein的化学和酶裂解产生的肽的序列分析的结果。该序列与铜绿假单胞菌的细胞色素c过氧化物酶有60%的相似性，与大肠杆菌中编码推定的三血红素c型细胞色素的开放阅读框有39%的相似性，与两种甲基营养型细菌的MauG蛋白有很大的相似性。有人建议，在序列中的保守残基的模式的基础上，在N-末端血红素结构域中的铁配位的变化可能伴随着减少到活性混合价态，这可能是伴随着构象调整的N-和C-末端结构域之间的高度保守的接口的变化。这些构象调整也可能导致混合价酶中出现第二个Ca 2+结合位点。血红素的C-末端结构域中的暴露的边缘被几种不同的模式的带电残基在副球菌和假单胞菌酶包围，这是一致的，与供体细胞色素c-550的高度正电荷的前面的相互作用的前者。
The amino acid sequence of the diheme cytochrome c peroxidase from Paracoccus denitrificans has been determined as the result of sequence analysis of peptides generated by chemical and enzymatic cleavages of the apoprotein. The sequence shows 60% similarity to the cytochrome c peroxidase from Pseudomonas aeruginosa, 39% similarity to an open reading frame encoding a putative triheme c-type cytochrome in Escherichia coli, and remote similarity to the MauG proteins from two methylotrophic bacteria. It is proposed, on the basis of the pattern of conserved residues in the sequences, that a change in iron coordination in the N-terminal heme domain may accompany reduction to the active mixed valence state, a change which may be accompanied by conformational adjustments in the highly conserved interface between the N- and C-terminal domains. These conformational adjustments may also lead to the appearance of a second Ca2+ binding site in the mixed valence enzyme. The exposed edge of the heme in the C-terminal domain is surrounded by several different patterns of charged residues in the Paracoccus and Pseudomonas enzymes, and this is consistent with the interaction of the former with the highly positively charged front face of the donor cytochrome c-550.