PMID: 12234918 , Related PDB ids: 1JPE, 1JZD, 1JZO

Authors:

Haebel PW, Goldstone D, Katzen F, Beckwith J, Metcalf P

Title:

The disulfide bond isomerase DsbC is activated by an immunoglobulin-fold thiol oxidoreductase: crystal structure of the DsbC-DsbDalpha complex.

Journal:

EMBO J. 2002 Sep 16;21(18):4774-84.

Abstract:

The Escherichia coli disulfide bond isomerase DsbC rearranges incorrect disulfide bonds during oxidative protein folding. It is specifically activated by the periplasmic N-terminal domain (DsbDalpha) of the transmembrane electron transporter DsbD. An intermediate of the electron transport reaction was trapped, yielding a covalent DsbC-DsbDalpha complex. The 2.3 A crystal structure of the complex shows for the first time the specific interactions between two thiol oxidoreductases. DsbDalpha is a novel thiol oxidoreductase with the active site cysteines embedded in an immunoglobulin fold. It binds into the central cleft of the V-shaped DsbC dimer, which assumes a closed conformation on complex formation. Comparison of the complex with oxidized DsbDalpha reveals major conformational changes in a cap structure that regulates the accessibility of the DsbDalpha active site. Our results explain how DsbC is selectively activated by DsbD using electrons derived from the cytoplasm.