2GOV

Solution structure of Murine p22HBP

Summary for 2GOV

• Entry DOI: 10.2210/pdb2gov/pdb
• NMR Information: BMRB: 6620
• Descriptor: Heme-binding protein 1 (1 entity in total)
• Functional Keywords: p22hbp, heme binding, structural genomics, protein structure initiative, psi, center for eukaryotic structural genomics, cesg, heme binding protein
• Biological source: Mus musculus (house mouse)
• Cellular location: Cytoplasm: Q9R257
• Total number of polymer chains: 1
• Total formula weight: 21777.39

Authors

Volkman, B.F.,Dias, J.S.,Goodfellow, B.J.,Peterson, F.C.,Center for Eukaryotic Structural Genomics (CESG) (deposition date: 2006-04-14, release date: 2006-05-09, Last modification date: 2024-05-29)

Primary citation

Dias, J.S.,Macedo, A.L.,Ferreira, G.C.,Peterson, F.C.,Volkman, B.F.,Goodfellow, B.J.
The First Structure from the SOUL/HBP Family of Heme-binding Proteins, Murine P22HBP.
J.Biol.Chem., 281:31553-31561, 2006

PubMed Abstract: 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.

PubMed: 16905545
DOI: 10.1074/jbc.M605988200

Experimental method

SOLUTION NMR