4ILF

Crystal structure of DsbC R125A from Salmonella enterica serovar Typhimurium

Summary for 4ILF

• Entry DOI: 10.2210/pdb4ilf/pdb
• Descriptor: Thiol:disulfide interchange protein DsbC (2 entities in total)
• Functional Keywords: cxxc motif, disulfide isomerase, isomerase
• Biological source: Salmonella typhimurium
• Cellular location: Periplasm: P55890
• Total number of polymer chains: 2
• Total formula weight: 48295.29

Authors

Ha, N.C.,Li, J.,Kim, J.S.,Yoon, B.Y.,Yeom, J.H.,Lee, K. (deposition date: 2012-12-31, release date: 2013-10-16, Last modification date: 2017-11-15)

Primary citation

Jiao, L.,Kim, J.S.,Song, W.S.,Yoon, B.Y.,Lee, K.,Ha, N.C.
Crystal structure of the periplasmic disulfide-bond isomerase DsbC from Salmonella enterica serovar Typhimurium and the mechanistic implications.
J.Struct.Biol., 183:1-10, 2013

PubMed Abstract: The disulfide-bond isomerase DsbC plays a crucial role in the folding of bacterial proteins in the periplasmic space. DsbC has a V-shaped dimeric structure with two domains, and Cys98 in the C-terminal domain attacks inappropriate disulfide bonds in substrate proteins due to its high nucleophilic activity. In this article, we present the crystal structure of DsbC from Salmonella enterica serovar Typhimurium. We evaluated the conserved residues Asp95 and Arg125, which are located close to Cys98. The mutation of Asp95 or Arg125 abolished the disulfide isomerase activity of DsbC in an in vitro assay using a protein substrate, and the R125A mutation significantly reduced the chaperone activity for the substrate RNase I in vivo. Furthermore, a comparative analysis suggested that the conformation of Arg125 varies depending on the packing or protein-protein interactions. Based on these findings, we suggest that Asp95 and Arg125 modulate the pKa of Cys98 during catalysis.

PubMed: 23726983
DOI: 10.1016/j.jsb.2013.05.013

Experimental method

X-RAY DIFFRACTION (1.999 Å)