Edwards TE, Bryan CM, Leibly DJ, Dieterich SH, Abendroth J, Sankaran B, Sivam D, Staker BL, Van Voorhis WC, Myler PJ, Stewart LJ. Structures of a putative ζ-class glutathione S-transferase from the pathogenic fungus Coccidioides immitis.
Acta Crystallogr Sect F Struct Biol Cryst Commun 2011;
67:1038-43. [PMID:
21904047 PMCID:
PMC3169399 DOI:
10.1107/s1744309111009493]
[Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2010] [Accepted: 03/12/2011] [Indexed: 11/25/2022]
Abstract
Coccidioides immitis is a pathogenic fungus populating the southwestern United States and is a causative agent of coccidioidomycosis, sometimes referred to as Valley Fever. Although the genome of this fungus has been sequenced, many operons are not properly annotated. Crystal structures are presented for a putative uncharacterized protein that shares sequence similarity with ζ-class glutathione S-transferases (GSTs) in both apo and glutathione-bound forms. The apo structure reveals a nonsymmetric homodimer with each protomer comprising two subdomains: a C-terminal helical domain and an N-terminal thioredoxin-like domain that is common to all GSTs. Half-site binding is observed in the glutathione-bound form. Considerable movement of some components of the active site relative to the glutathione-free form was observed, indicating an induced-fit mechanism for cofactor binding. The sequence homology, structure and half-site occupancy imply that the protein is a ζ-class glutathione S-transferase, a maleylacetoacetate isomerase (MAAI).
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