THE ACTIVE-SITE OF METHANOL DEHYDROGENASE CONTAINS A DISULFIDE BRIDGE BETWEEN ADJACENT CYSTEINE RESIDUES
THE ACTIVE-SITE OF METHANOL DEHYDROGENASE CONTAINS A DISULFIDE BRIDGE BETWEEN ADJACENT CYSTEINE RESIDUES
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DOI：
10.1038/nsb0294-102
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发表时间：
1994-02-01
期刊：
影响因子：
--
通讯作者：
ANTHONY, C
中科院分区：
文献类型：
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作者：
BLAKE, CCF;GHOSH, M;ANTHONY, C
相邻的半胱氨酸残基只能在含有顺式肽连接的扭曲结构中形成二硫桥。这种桥是非常罕见的，迄今为止仅在乙酰胆碱受体中发现，其中桥的结构尚未确定。在这里，我们提出了在来自扭脱甲基杆菌的醌蛋白甲醇脱氢酶中的这种类型的二硫桥的第一个分子描述。我们发现，这种结构发生在接近吡咯并喹啉醌辅基和钙离子的酶的活性位点。这种不寻常的二硫桥似乎在甲醇脱氢酶介导的电子转移反应中发挥作用。
Adjacent cysteine residues can only form disulphide bridges in a distorted structure containing a cis-peptide link. Such bridges are extremely uncommon, identified so far in the acetyl choline receptor alone where the structure of the bridge is undetermined. here we present the first molecular description of a disulphide bridge of this type in the quinoprotein methanol dehydrogenase from Methylobacterium extorquens. We show that this structure occurs in close proximity to the pyrrolo-quinoline quinone prosthetic group and a calcium ion in the active site of the enzyme. This unusual disulphide bridge appears to play a role in the electron transfer reaction mediated by methanol dehydrogenase.