Structural and functional characterization of HP0377, a thioredoxin-fold protein from Helicobacter pyloriYoon, J.Y., Kim, J., An, D.R., Lee, S.J., Kim, H.S., Im, H.N., Yoon, H.J., Kim, J.Y., Kim, S.J., Han, B.W., Suh, S.W.
(2013) Acta Crystallogr.,Sect.D 69: 735-746
- PubMed: 23633582
- DOI: 10.1107/S0907444913001236
- Primary Citation of Related Structures:
- PubMed Abstract:
Maturation of cytochrome c is carried out in the bacterial periplasm, where specialized thiol-disulfide oxidoreductases provide the correct reduction of oxidized apocytochrome c before covalent haem attachment. HP0377 from Helicobacter pylori is a th ...
Maturation of cytochrome c is carried out in the bacterial periplasm, where specialized thiol-disulfide oxidoreductases provide the correct reduction of oxidized apocytochrome c before covalent haem attachment. HP0377 from Helicobacter pylori is a thioredoxin-fold protein that has been implicated as a component of system II for cytochrome c assembly and shows limited sequence similarity to Escherichia coli DsbC, a disulfide-bond isomerase. To better understand the role of HP0377, its crystal structures have been determined in both reduced and partially oxidized states, which are highly similar to each other. Sedimentation-equilibrium experiments indicate that HP0377 is monomeric in solution. HP0377 adopts a thioredoxin fold but shows distinctive variations as in other thioredoxin-like bacterial periplasmic proteins. The active site of HP0377 closely resembles that of E. coli DsbC. A reductase assay suggests that HP0377 may play a role as a reductase in the biogenesis of holocytochrome c553 (HP1227). Binding experiments indicate that it can form a covalent complex with HP0518, a putative L,D-transpeptidase with a catalytic cysteine residue, via a disulfide bond. Furthermore, physicochemical properties of HP0377 and its R86A variant have been determined. These results suggest that HP0377 may perform multiple functions as a reductase in H. pylori.
Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul 151-742, Republic of Korea.