Structures of the dimerization domains of the Escherichia coli disulfide-bond isomerase enzymes DsbC and DsbG.
DsbC and DsbG are periplasmic disulfide-bond isomerases, enzymes that facilitate the folding of secreted proteins with multiple disulfide bonds by catalyzing disulfide-bond rearrangement. Both enzymes also have in vitro chaperone activity. The crystal structures of these molecules are similar and both are V-shaped homodimeric modular structures. Each dimeric molecule contains two separate C-terminal thioredoxin-fold domains, joined by hinged helical "stalks" to a single N-terminal dimerization domain formed from the N-terminal 67 residues of each monomer. In this work, the crystal structures of the separate DsbC and DsbG dimerization domains have been determined at resolutions of 2.0 and 1.9 A, respectively. The two structures are both similar to the corresponding domains in the full-length molecules, showing that the dimerization domains fold independently of the catalytic portions of the full-length molecules. Localized structural differences between DsbC and DsbG were observed near the dimer interface and may be relevant to the different functions of the two enzymes.
Yeh
Shin Mei
SM
School of Biological Sciences, Auckland University, Auckland, New Zealand.
Koon
Nayden
N
Squire
Christopher
C
Metcalf
Peter
P
D000595:Amino Acid Sequence; D001665:Binding Sites; D020134:Catalytic Domain; D003460:Crystallization; D018360:Crystallography, X-Ray; D019281:Dimerization; D004926:Escherichia coli / Q000201:enzymology*; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019704:Protein Disulfide-Isomerases / Q000737:chemistry* / Q000378:metabolism; D017510:Protein Folding; D017386:Sequence Homology, Amino Acid
D029968:Escherichia coli Proteins; D019704:Protein Disulfide-Isomerases