The active site structure of the calcium-containing quinoprotein methanol dehydrogenase.
The active site structure of the calcium-containing quinoprotein methanol dehydrogenase.
复制标题
含钙醌蛋白甲醇脱氢酶的活性位点结构。
DOI：
10.1021/bi00211a002
复制
发表时间：
1993
期刊：
影响因子：
2.9
通讯作者：
Davidson,VL
中科院分区：
文献类型：
--
作者：
White,S;Boyd,G;Mathews,FS;Xia,ZX;Dai,WW;Zhang,YF;Davidson,VL
摘要：吡咯喹啉醌（PQQ），广泛存在于自然界中，作为细菌甲醇脱氢酶（MEDH）的氧化还原辅因子，MEDH是一种将甲醇氧化为甲醛的异四聚体酶。基于最近获得的氨基酸序列数据，在2.4-kDa分辨率下的MEDH的精细结构揭示了位于盘状蛋白质的中央通道中的PQQ夹在Trp侧链和非常不寻常的邻位二硫化物之间。Ca 2+离子在PQQ和蛋白质分子之间形成桥梁，非常接近推定的底物结合口袋。甲醇脱氢酶（Methanol dehydrogenase，MEDH）是一种位于革兰氏阴性甲基营养菌周质中的醌蛋白，分子量为140 kDa，能催化甲醇和其它伯醇氧化为相应的醛类。它是一种约2/82四聚体，亚基分子量分别为62和8 kDa，每个四聚体含有2 mol辅基吡咯并喹啉醌（PQQ）。副球菌两个亚基的氨基酸序列
Revised Manuscript Received October 14, 1993* abstract: Pyrroloquinoline quinone (PQQ), widely found in nature, serves as the redox cofactor in bacterial methanol dehydrogenase (MEDH), a heterotetrameric enzyme that oxidizes methanol to formaldehyde. The refined structure of MEDH at 2.4-Á resolution, based on recently obtained amino acid sequence data, reveals that the PQQ, located in a central channel of the disk-shaped protein, is sandwiched between a Trp side chain and a very unusual vicinal disulfide. A Ca2+ ion forms a bridge between PQQ and the protein molecule, very close to a putative substrate binding pocket. The vicinal disulfide may form during PQQ incorporation and possibly act to hold the latter in place.Methanol dehydrogenase (MEDH), 1 a quinoprotein of molecular mass 140 kDa located in the periplasm of many gram negative methylotrophic bacteria (Anthony, 1993), catalyzes the oxidation of methanol and otherprimary alcohols to their corresponding aldehydes. It is an «2/82 tetramer of approximate subunit molecular masses 62 and 8 kDa, respectively, and contains 2 mol of the prosthetic group pyrroloquinoline quinone (PQQ) per tetramer. The amino acid sequences of both subunitsfrom Paracoccus denitriflcans