Letter to the Editor:: 1H, 15N and 13C assignments of the carboxy-terminal domain of the transmembrane electron transfer protein DsbD
Letter to the Editor:: 1H, 15N and 13C assignments of the carboxy-terminal domain of the transmembrane electron transfer protein DsbD
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DOI：
10.1023/a:1021638313691
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发表时间：
2002-12-01
影响因子：
2.7
通讯作者：
Redfield, C
中科院分区：
文献类型：
--
作者：
Bushnell, KMW;Ferguson, SJ;Redfield, C
电子转移蛋白DsbD，也称为DipZ，存在于革兰氏阴性细菌的细胞质膜中，其独特之处在于其采用分子内二硫键级联将电子从细胞质硫氧还蛋白转移到周质二硫键异构酶DsbC和DsbG，并通过CcmG（DsbE）和/或CcmH转移到细胞色素c成熟途径（Rietsch和Beckwith，1998，及其参考文献）。DsbD由三个不同的结构域组成：在N-和C-末端的两个周质结构域，其被八个螺旋的跨膜结构域分开（Page等人，1997; Gordon等人，2000），在别处分别称为α、γ和β结构域（Katzen和Beckwith，2000）。每个结构域包含电子转移所必需的保守的半胱氨酸对，据信通过二硫键的顺序还原发生。最初，细胞质硫氧还蛋白还原跨膜结构域的二硫键，所得硫醇反过来还原C-末端结构域的二硫键，然后还原N-末端结构域的二硫键（Katzen和Beckwith，2000）。DsbD跨细胞质膜转运电子的机制的阐明是必不可少的各个域的结构和它们之间的相互作用。N-末端结构域的晶体结构最近已被公开（Goulding等人，2002），但是对于C-末端结构域没有相应的结构。DsbD的C-末端结构域在其活性位点含有CXXC-基序，其是硫醇-二硫键还原酶的硫氧还蛋白超家族的特征，
The electron transfer protein DsbD, also known as DipZ and found in the cytoplasmic membrane of Gram-negative bacteria, is unique in that it employs an intra-molecular disulfide cascade to transfer electrons from cytoplasmic thioredoxin to the periplasmic disulfide isomerases, DsbC and DsbG, and to the cytochrome c maturation pathway via CcmG (DsbE) and/or CcmH (Rietsch and Beckwith, 1998, and references therein). DsbD consists of three distinct domains: two periplasmic domains at the N-and C-termini which are separated by a transmembrane domain of eight helices (Page et al., 1997; Gordon et al., 2000), referred to elsewhere as the α, γ and β domains, respectively (Katzen and Beckwith, 2000). Each domain contains a conserved pair of cysteines essential for electron transfer, believed to occur via the sequential reduction of disulfide bonds. Initially cytoplasmic thioredoxin reduces the disulfide bond of the transmembrane domain, the resulting thiols in turn reduce the disulfide bond of the C-terminal domain, which then reduces the disulfide bond of the N-terminal domain (Katzen and Beckwith, 2000). Essential for elucidation of the mechanism by which DsbD transports electrons across the cytoplasmic membrane are the structures of the individual domains and the interactions between them. The crystal structure of the N-terminal domain has recently been published (Goulding et al., 2002), but there is no corresponding structure for the C-terminal domain. The C-terminal domain of DsbD contains a CXXC-motif at its active site, characteristic of the thioredoxin superfamily of thiol-disulfide reductases,