1NX7 image
Deposition Date 2003-02-10
Release Date 2004-06-15
Last Version Date 2024-05-29
Entry Detail
PDB ID:
1NX7
Title:
Solution Structure of Oxidized Bovine Microsomal Cytochrome B5
Biological Source:
Source Organism:
Bos taurus (Taxon ID: 9913)
Host Organism:
Method Details:
Experimental Method:
Conformers Submitted:
30
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:Cytochrome B5
Gene (Uniprot):CYB5A
Chain IDs:A
Chain Length:82
Number of Molecules:1
Biological Source:Bos taurus
Ligand Molecules
Primary Citation
The comparative study on the solution structures of the oxidized bovine microsomal cytochrome b5 and mutant V45H
Protein Sci. 13 2161 2169 (2004)
PMID: 15273310 DOI: 10.1110/ps.04721104

Abstact

A comparative study on the solution structures of bovine microsomal cytochrome b5 (Tb5) and the mutant V45H has been achieved by 1D and 2D 1H-NMR spectroscopy to clarify the differences in the solution conformations between these two proteins. The results reveal that the global folding of the V45H mutant in solution is unchanged, but the subtle changes exist in the orientation of the axial ligand His39, and heme vinyl groups. The side chain of His45 in V45H mutant extends to the outer edge of the heme pocket leaving a cavity at the site originally occupied by the inner methyl group of Val45 residue. In addition, the imidazole ring of axial ligand His39 rotates counterclockwise by approximately 3 degrees around the His-Fe-His axis, and the 4-heme vinyl group turns to the space vacated by the removed side chain due to the mutation. Furthermore, the helix III of the heme pocket undergoes outward displacement, while the linkage between helix II and III is shifted leftward. These observations are not only consistent with the pattern of the pseudocontact shifts of the heme protons, but also well account for the lower stability of V45H mutant against heat and urea.

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Primary Citation of related structures