2p9q
Crystal Structure of Phosphoglycerate Kinase-2
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OverviewOverview
Phosphoglycerate kinase 2 (PGK2) is an isozyme of the glycolytic pathway, that provides ATP required for sperm motility. It is encoded by an, autosomal retrogene that is expressed only during spermatogenesis, concomitant with the inactivation of the X-linked Pgk1 gene. PGK2 from the, mouse, Mus musculus, has been overexpressed from a plasmid in bacteria and, purified. It was crystallized in three forms: as the apoenzyme, as a, complex with 3-phosphoglycerate (3PG), and as a complex with 3PG and ATP., The crystal structures were solved to 2.7, 2.0, and 2.7 A resolutions, respectively. The overall fold is nearly identical with previously solved, mammalian PGK1 molecules. The apoenzyme is in the "open" form; that is the, N-terminal domain that can bind 3PG and the C-terminal domain that binds, ATP are too far apart for the substrates to interact. Binding 3PG causes a, 13 degrees rotation that partially closes the structure and causes helix, 13, which is disordered in the unliganded structure, to stabilize. Binding, ATP leaves the protein in the open configuration but also causes helix 13, to be ordered. Sequence alignment suggests that the active site of PGK2 is, essentially identical to that of the cytoplasmic PGK1, but significant, differences accumulate on a side of the C-terminal domain away from the, active site. These changes may mediate the binding of this isoform to, other proteins within the sperm flagellum, while still allowing the, hinging action between the domains that is essential to catalytic, activity. Proteins 2007. (c) 2007 Wiley-Liss, Inc.
About this StructureAbout this Structure
2P9Q is a Single protein structure of sequence from Mus musculus. Active as Phosphoglycerate kinase, with EC number 2.7.2.3 Full crystallographic information is available from OCA.
ReferenceReference
X-ray analysis of phosphoglycerate kinase 2, a sperm-specific isoform from Mus musculus., Sawyer GM, Monzingo AF, Poteet EC, O'Brien DA, Robertus JD, Proteins. 2007 Nov 14;. PMID:18004764
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