2fy6 | pdb_00002fy6
Structure of the N-terminal domain of Neisseria meningitidis PilB
Structural highlights
Function[MSRAB_NEIMA] Has an important function as a repair enzyme for proteins that have been inactivated by oxidation (By similarity). Catalyzes the reversible oxidation-reduction of methionine sulfoxide in proteins to methionine. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe secreted form of the PilB protein was recently shown to be bound to the outer membrane of Neisseria gonorrhoeae and proposed to be involved in survival of the pathogen to the host's oxidative burst. PilB is composed of three domains. The central and the C-terminal domains display methionine sulfoxide reductase (Msr) A and B activities respectively, i.e. the ability to reduce specifically the S and the R enantiomers of the sulfoxide function of the methionine sulfoxides, which are easily formed upon oxidation of methionine residues. The N-terminal domain of PilB (Dom1(PILB)) of N.meningitidis, which possesses a CXXC motif, was recently shown to recycle the oxidized forms of the PilB Msr domains in vitro, as the Escherichia coli thioredoxin (Trx) 1 does. The X-ray structure of Dom1(PILB) of N.meningitidis determined here shows a Trx-fold, in agreement with the biochemical properties of Dom1(PILB). However, substantial structural differences with E.coli Trx1 exist. Dom1(PILB) displays more structural homologies with the periplasmic disulfide oxidoreductases involved in cytochrome maturation pathways in bacteria. The active site of the reduced form of Dom1(PILB) reveals a high level of stabilization of the N-terminal catalytic cysteine residue and a hydrophobic environment of the C-terminal recycling cysteine in the CXXC motif, consistent with the pK(app) values measured for Cys67 (<6) and Cys70 (9.3), respectively. Compared to cytochrome maturation disulfide oxidoreductases and to Trx1, one edge of the active site is covered by four additional residues (99)FLHE(102). The putative role of the resulting protuberance is discussed in relation to the disulfide reductase properties of Dom1(PILB). The X-ray structure of the N-terminal domain of PILB from Neisseria meningitidis reveals a thioredoxin-fold.,Ranaivoson FM, Kauffmann B, Neiers F, Wu J, Boschi-Muller S, Panjikar S, Aubry A, Branlant G, Favier F J Mol Biol. 2006 Apr 28;358(2):443-54. Epub 2006 Feb 28. PMID:16530221[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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