Ito Koreaki, Inaba Kenji
Institute for Virus Research, Kyoto University, Kyoto, Japan.
Curr Opin Struct Biol. 2008 Aug;18(4):450-8. doi: 10.1016/j.sbi.2008.02.002. Epub 2008 Apr 11.
In oxidative folding of proteins in the bacterial periplasmic space, disulfide bonds are introduced by the oxidation system and isomerized by the reduction system. These systems utilize the oxidizing and the reducing equivalents of quinone and NADPH, respectively, that are transmitted across the cytoplasmic membrane through integral membrane components DsbB and DsbD. In both pathways, alternating interactions between a Cys-XX-Cys-containing thioredoxin domain and other regulatory domain lead to the maintenance of oxidized and reduced states of the specific terminal enzymes, DsbA that oxidizes target cysteines and DsbC that reduces an incorrect disulfide to allow its isomerization into the physiological one. Molecular details of these remarkable biochemical cascades are being rapidly unraveled by genetic, biochemical, and structural analyses in recent years.
在细菌周质空间中蛋白质的氧化折叠过程中，二硫键由氧化系统引入，并由还原系统异构化。这些系统分别利用醌和NADPH的氧化和还原当量，它们通过整合膜成分DsbB和DsbD穿过细胞质膜进行传递。在这两条途径中，含半胱氨酸-XX-半胱氨酸的硫氧还蛋白结构域与其他调节结构域之间的交替相互作用导致特定末端酶DsbA（氧化靶标半胱氨酸）和DsbC（还原错误的二硫键以使其异构化为生理状态的二硫键）维持氧化态和还原态。近年来，通过遗传、生化和结构分析，这些显著生化级联反应的分子细节正在迅速被揭示。
