1I5U

SOLUTION STRUCTURE OF CYTOCHROME B5 TRIPLE MUTANT (E48A/E56A/D60A)

Summary for 1I5U

• Entry DOI: 10.2210/pdb1i5u/pdb
• Related: 1F04 1I5T 1aw3
• Descriptor: CYTOCHROME B5, PROTOPORPHYRIN IX CONTAINING FE (2 entities in total)
• Functional Keywords: electron transport, transmembrane, heme, microsome
• Biological source: Bos taurus (cattle)
• Cellular location: Endoplasmic reticulum membrane; Single-pass membrane protein; Cytoplasmic side: P00171
• Total number of polymer chains: 1
• Total formula weight: 9931.78

Authors

Qian, C.,Yao, Y.,Tang, W.,Wang, J.,Zhongxian, H. (deposition date: 2001-02-28, release date: 2001-03-21, Last modification date: 2024-05-29)

Primary citation

Qian, C.,Yao, Y.,Ye, K.,Wang, J.,Tang, W.,Wang, Y.,Wang, W.,Lu, J.,Xie, Y.,Huang, Z.
Effects of charged amino-acid mutation on the solution structure of cytochrome b(5) and binding between cytochrome b(5) and cytochrome c.
Protein Sci., 10:2451-2459, 2001

PubMed Abstract: The solution structure of oxidized bovine microsomal cytochrome b(5) mutant (E48, E56/A, D60/A) has been determined through 1524 meaningful nuclear Overhauser effect constraints together with 190 pseudocontact shift constraints. The final family of 35 conformers has rmsd values with respect to the mean structure of 0.045+/-0.009 nm and 0.088+/-0.011 nm for backbone and heavy atoms, respectively. A characteristic of this mutant is that of having no significant changes in the whole folding and secondary structure compared with the X-ray and solution structures of wild-type cytochrome b(5). The binding of different surface mutants of cytochrome b(5) with cytochrome c shows that electrostatic interactions play an important role in maintaining the stability and specificity of the protein complex formed. The differences in association constants demonstrate the electrostatic contributions of cytochrome b(5) surface negatively charged residues, which were suggested to be involved in complex formation in the Northrup and Salemme models, have cumulative effect on the stability of cyt c-cyt b(5) complex, and the contribution of Glu48 is a little higher than that of Glu44. Moreover, our result suggests that the docking geometry proposed by Northrup, which is involved in the participation of Glu48, Glu56, Asp60, and heme propionate of cytochrome b(5), do occur in the association between cytochrome b(5) and cytochrome c.

PubMed: 11714912
DOI: 10.1110/ps.ps.12401

Experimental method

SOLUTION NMR