Yamashita Eiki, Aoyama Hiroshi, Yao Min, Muramoto Kazumasa, Shinzawa-Itoh Kyoko, Yoshikawa Shinya, Tsukihara Tomitake
Institute for Protein Research, Osaka University, 3-2 Yamada-oka, Suita 565-0871, Japan.
Acta Crystallogr D Biol Crystallogr. 2005 Oct;61(Pt 10):1373-7. doi: 10.1107/S0907444905023358. Epub 2005 Sep 28.
The absolute configuration of haem A, the prosthetic group of cytochrome c oxidase, was determined to be S by analysis of the bond angles surrounding the chiral centre of haem A after refinement with X-PLOR starting from respective initial structures with R and S configurations under absolute configuration constraints at 1.8 Angstrom resolution. The same result was obtained by refinement at 1.8 Angstrom resolution without the absolute configuration constraints. Both of these methods were applicable down to a resolution of about 2.8 Angstrom. The constrained refinement converges more quickly than the unconstrained refinement.
