2gov
From Proteopedia
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Solution structure of Murine p22HBP
Overview
Murine p22HBP, a 22-kDa monomer originally identified as a cytosolic, heme-binding protein ubiquitously expressed in various tissues, has 27%, sequence identity to murine SOUL, a heme-binding hexamer specifically, expressed in the retina. In contrast to murine SOUL, which binds one heme, per subunit via coordination of the Fe(III)-heme to a histidine, murine, p22HBP binds one heme molecule per subunit with no specific axial ligand, coordination of the Fe(III)-heme. Using intrinsic protein fluorescence, quenching, the values for the dissociation constants of p22HBP for hemin, and protoporphyrin-IX were determined to be in the low nanomolar range., The three-dimensional structure of murine p22HBP, the first for a protein, from the SOUL/HBP family, was determined by NMR methods to consist of a, 9-stranded distorted beta-barrel flanked by two long alpha-helices., Although homologous domains have been found in three bacterial proteins, two of which are transcription factors, the fold determined for p22HBP, corresponds to a novel alpha plus beta fold in a eukaryotic protein., Chemical shift mapping localized the tetrapyrrole binding site to a, hydrophobic cleft formed by residues from helix alphaA and an extended, loop. In an attempt to assess the structural basis for tetrapyrrole, binding in the SOUL/HBP family, models for the p22HBP-protoporphyrin-IX, complex and the SOUL protein were generated by manual docking and, automated methods.
About this Structure
2GOV is a Single protein structure of sequence from Mus musculus. Full crystallographic information is available from OCA.
Reference
The first structure from the SOUL/HBP family of heme-binding proteins, murine P22HBP., Dias JS, Macedo AL, Ferreira GC, Peterson FC, Volkman BF, Goodfellow BJ, J Biol Chem. 2006 Oct 20;281(42):31553-61. Epub 2006 Aug 10. PMID:16905545
Page seeded by OCA on Wed Nov 21 11:18:48 2007
