1BFX: THE SOLUTION NMR STRUCTURE OF THE B FORM OF OXIDIZED RAT MICROSOMAL CYTOCHROME B5, MINIMIZED AVERAGE STRUCTURE

Citation:
Abstract
Cytochrome b5 in solution has two isomers (A and B) differing by a 180 degrees rotation of the protoporphyrin IX plane around the axis defined by the alpha and gamma meso protons. Homonuclear and heteronuclear NMR spectroscopy has been employed in order to solve the solution structure of the minor (B) form of the oxidized state of the protein and to probe its backbone dynamics in the microsecond--ms timescale in both oxidation states. A family of 40 conformers has been obtained using 1302 meaningful NOEs and 220 pseudocontact shifts and is characterized by high quality and good resolution (rmsd to the mean structure of 0.055 +/- 0.009 nm and 0.103 +/- 0.011 nm for backbone and heavy atoms, respectively). Extensive comparisons of the structural and dynamics changes associated with the A-to-B form interconversion for both oxidation states were subsequently performed. Propionate 6 experiences a redox-state-dependent reorientation as does propionate 7 in the A form. Significant insights are obtained into the role of the protein frame for efficient biological function and backbone mobility is proposed to be one of the factors that could control the reduction potential of the heme.
PDB ID: 1BFXDownload
MMDB ID: 162284
PDB Deposition Date: 1998/5/23
Updated in MMDB: 2018/05
Experimental Method:
solution nmr
Source Organism:
Similar Structures:
Molecular Components in 1BFX
Label Count Molecule
Protein (1 molecule)
1
Cytochrome B5(Gene symbol: Cyb5a)
Molecule annotation
Chemical (1 molecule)
1
1
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