Journal Article

PHPPUBDB-24733

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Structural basis for the oxidation of protein-bound sulfur by the sulfur cycle molybdohemo-enzyme sulfane dehydrogenase SoxCD

Zander, U. ; Faust, A.Extern* ; Klink, B. U. ; de Sanctis, D. ; Panjikar, S.EMBL* ; Quentmeier, A. ; Bardischewsky, F. ; Friedrich, C. G. (Corresponding author) ; Scheidig, A. J. (Corresponding author) ; DESY

2011
Soc. Bethesda, Md.

This record in other databases:        

Please use a persistent id in citations: doi:10.1074/jbc.M110.193631

Abstract: The sulfur cycle enzyme sulfane dehydrogenase SoxCD is an essential component of the sulfur oxidation (Sox) enzyme system of Paracoccus pantotrophus. SoxCD catalyzes a six-electron oxidation reaction within the Sox cycle. SoxCD is an α(2)β(2) heterotetrameric complex of the molybdenum cofactor-containing SoxC protein and the diheme c-type cytochrome SoxD with the heme domains D(1) and D(2). SoxCD(1) misses the heme-2 domain D(2) and is catalytically as active as SoxCD. The crystal structure of SoxCD(1) was solved at 1.33 Å. The substrate of SoxCD is the outer (sulfane) sulfur of Cys-110-persulfide located at the C-terminal peptide swinging arm of SoxY of the SoxYZ carrier complex. The SoxCD(1) substrate funnel toward the molybdopterin is narrow and partially shielded by side-chain residues of SoxD(1). For access of the sulfane-sulfur of SoxY-Cys-110 persulfide we propose that (i) the blockage by SoxD-Arg-98 is opened via interaction with the C terminus of SoxY and (ii) the C-terminal peptide VTIGGCGG of SoxY provides interactions with the entrance path such that the cysteine-bound persulfide is optimally positioned near the molybdenum atom. The subsequent oxidation reactions of the sulfane-sulfur are initiated by the nucleophilic attack of the persulfide anion on the molybdenum atom that is, in turn, reduced. The close proximity of heme-1 to the molybdopterin allows easy acceptance of the electrons. Because SoxYZ, SoxXA, and SoxB are already structurally characterized, with SoxCD(1) the structures of all key enzymes of the Sox cycle are known with atomic resolution.

Keyword(s): Bacterial Proteins: chemistry (MeSH) ; Bacterial Proteins: genetics (MeSH) ; Crystallography, X-Ray (MeSH) ; Molybdenum: chemistry (MeSH) ; Oxidation-Reduction (MeSH) ; Oxidoreductases: chemistry (MeSH) ; Oxidoreductases: genetics (MeSH) ; Paracoccus pantotrophus: enzymology (MeSH) ; Paracoccus pantotrophus: genetics (MeSH) ; Peptides: chemistry (MeSH) ; Peptides: genetics (MeSH) ; Protein Structure, Quaternary (MeSH) ; Protein Structure, Tertiary (MeSH) ; Structure-Activity Relationship (MeSH) ; Sulfur: chemistry (MeSH) ; Bacterial Proteins ; Peptides ; Molybdenum ; Sulfur ; Oxidoreductases

Note: (c) by The American Society for Biochemistry and Molecular Biology, Inc. Post referee fulltext in progress. Code P.

---

Contributing Institute(s):

1. EMBL (EMBL(-2012))

Research Program(s):

1. FS Beamline without reference (POF2-544) (POF2-544)

Experiment(s):

1. Unknown DESY Beamline

Appears in the scientific report 2011

---

Database coverage:
; BIOSIS Previews ; Current Contents - Life Sciences ; JCR ; NCBI Molecular Biology Database ; No Author Disambiguation ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection

---