Open AccessStructures of a putative ζ‐class glutathione S ‐transferase from the pathogenic fungus Coccidioides immitis
Author(s) -
Edwards Thomas E.,
Bryan Cassie M.,
Leibly David J.,
Dieterich Shellie H.,
Abendroth Jan,
Sankaran Banumathi,
Sivam Dhileep,
Staker Bart L.,
Van Voorhis Wesley C.,
Myler Peter J.,
Stewart Lance J.
Publication year - 2011
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
ISSN - 1744-3091
DOI - 10.1107/s1744309111009493
Subject(s) - coccidioides immitis , biology , glutathione , binding site , biochemistry , isomerase , thioredoxin , microbiology and biotechnology , enzyme
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).