4FYB: Structural And Functional Characterizations Of A Thioredoxin-fold Protein From Helicobacter Pylori

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.
PDB ID: 4FYBDownload
MMDB ID: 109857
PDB Deposition Date: 2012/7/4
Updated in MMDB: 2013/09
Experimental Method:
x-ray diffraction
Resolution: 2.2  Å
Source Organism:
Similar Structures:
Biological Unit for 4FYB: monomeric; determined by author and by software (PISA)
Molecular Components in 4FYB
Label Count Molecule
Protein (1 molecule)
Thiol:disulfide Interchange Protein (Dsbc)
Molecule annotation
* Click molecule labels to explore molecular sequence information.

Citing MMDB