2AXX

THE SOLUTION STRUCTURE OF OXIDIZED RAT MICROSOMAL CYTOCHROME B5, NMR, 21 STRUCTURES

2AXX の概要

• エントリーDOI: 10.2210/pdb2axx/pdb
• 分子名称: CYTOCHROME B5, PROTOPORPHYRIN IX CONTAINING FE (2 entities in total)
• 機能のキーワード: cytochrome b5, protein recognition, electron transfer, solution structure, paramagnetic nmr, electron transport
• 由来する生物種: Rattus norvegicus (Norway rat)
• 細胞内の位置: Endoplasmic reticulum membrane; Single-pass membrane protein; Cytoplasmic side: P00173
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 11430.39

構造登録者

Arnesano, F.,Banci, L.,Bertini, I.,Felli, I.C. (登録日: 1997-10-22, 公開日: 1998-03-04, 最終更新日: 2024-05-01)

主引用文献

Arnesano, F.,Banci, L.,Bertini, I.,Felli, I.C.
The solution structure of oxidized rat microsomal cytochrome b5.
Biochemistry, 37:173-184, 1998

PubMed Abstract: The solution structure of oxidized rat microsomal cytochrome b5 has been obtained from 1H NMR spectra measured at 800 MHz. The available assignment has been extended to 78% of the total protons and 95% of the residues. From 1372 meaningful NOEs, a family of 40 structures has been obtained through the program DYANA; 235 pseudocontact shifts have been then added as further constraints, obtaining an essentially similar family of structures. This latter family has been further refined through restrained energy minimization. The final RMSD values with respect to the average structure are 0.58 +/- 0.10 A and 1.05 +/- 0.11 A for backbone and heavy atoms, respectively. The high quality of the structure allows meaningful comparisons with the solution structure of the reduced protein, with the X-ray and solution structures of the oxidized bovine isoenzyme, and with the solution structure of the apoprotein. Upon loss of one electron, the heme plane undergoes a change in its orientation, possibly due to the change of the total charge. Propionate 7 appears to have a conformation which is dependent on the oxidation state of the iron. Helices alpha2 and alpha4 also experience changes in their average positions in the two oxidation states. Finally, the backbone NHs experience different exchange properties in the two oxidation states. While those present in the beta sheets forming the basis of the heme pocket are nonexchanging in both oxidation states, the NHs in the helices forming the heme-binding pocket are exchanging with the bulk solvent in the oxidized form, indicating larger local mobility in this state. This observation could suggest that, to optimize the electron transfer process, the local mobility should be properly tuned.

PubMed: 9425037
DOI: 10.1021/bi971896w

実験手法

SOLUTION NMR