4gqc

Crystal Structure of Aeropyrum pernix Peroxiredoxin Q Enzyme in Fully-Folded and Locally-Unfolded Conformations

spinqualitylabelsall models 4gqc, resolution 2.00Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4gqc is a 4 chain structure with sequence from Aeropyrum pernix K1. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2Å Ligands: DTD, GOL, SO4 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function Q9YA14_AERPE Publication Abstract from PubMed Peroxiredoxins (Prx) make up a family of enzymes that reduce peroxides using a peroxidatic cysteine residue; among these, members of the PrxQ subfamily are proposed to be the most ancestral-like yet are among the least characterized. In many PrxQ enzymes, a second "resolving" cysteine is located five residues downstream from the peroxidatic Cys, and these residues form a disulfide during the catalytic cycle. Here, we describe three hyperthermophilic PrxQ crystal structures originally determined by the RIKEN structural genomics group. We reprocessed the diffraction data and conducted further refinement to yield models with R(free) values lowered by 2.3-7.2% and resolution extended by 0.2-0.3 A, making one, at 1.4 A, one of the best resolved peroxiredoxins to date. Comparisons of two matched thiol and disulfide forms reveal that the active site conformational change required for disulfide formation involves a transition of approximately 20 residues from a pair of alpha-helices to a beta-hairpin and 3(10)-helix. Each conformation has approximately 10 residues with a high level of disorder providing slack that allows the dramatic shift, and the two conformations are anchored to the protein core by distinct nonpolar side chains that fill three hydrophobic pockets. Sequence conservation patterns confirm the importance of these and a few additional residues for function. From a broader perspective, this study raises the provocative question of how to make use of the valuable information in the Protein Data Bank generated by structural genomics projects but not described in the literature, perhaps remaining unrecognized and certainly underutilized. Mapping the Active Site Helix-to-Strand Conversion of CxxxxC Peroxiredoxin Q Enzymes.,Perkins A, Gretes MC, Nelson KJ, Poole LB, Karplus PA Biochemistry. 2012 Sep 14. PMID:22928725 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Thiol peroxidase 3D structures

Proteopedia Page Contributors and Editors (what is this?)

OCA