Solution structure of thermostable cytochrome c-552 from Hydrogenobacter thermophilus determined by 1H-NMR spectroscopy.
Hasegawa, J., Yoshida, T., Yamazaki, T., Sambongi, Y., Yu, Y., Igarashi, Y., Kodama, T., Yamazaki, K., Kyogoku, Y., Kobayashi, Y.(1998) Biochemistry 37: 9641-9649
- PubMed: 9657676
- DOI: https://doi.org/10.1021/bi9803067
- Primary Citation of Related Structures:
1AYG - PubMed Abstract:
The solution structure of a thermostable cytochrome c-552 from a thermophilic hydrogen oxidizing bacterium Hydrogenobacter thermophilus was determined by proton nuclear magnetic resonance spectroscopy. Twenty structures were calculated by the X-PLOR program on the basis of 902 interproton distances, 21 hydrogen bonds, and 13 torsion angle constraints. The pairwise average root-mean-square deviation for the main chain heavy atoms was 0.91 +/- 0.11 A. The main chain folding of the cytochrome c-552 was almost the same as that of Pseudomonas aeruginosa cytochrome c-551 that has 59% sequence identity to the cytochrome c-552 but is less thermostable. We found several differences in local structures between the cytochromes c-552 and c-551. In the cytochrome c-552, aromatic-amino interactions were uniquely formed between Arg 35 and Tyr 32 and/or Tyr 41, the latter also having hydrophobic contacts with the side chains of Tyr 32, Ala 38, and Leu 42. Small hydrophobic cores were more tightly packed in the cytochrome c-552 because of the occupancies of Ala 5, Met 11, and Ile 76, each substituted by Phe 7, Val 13, and Val 78, respectively, in the cytochrome c-551. Some of these structural differences may contribute to the higher thermostability of the cytochrome c-552.
Organizational Affiliation:
Daiichi Pharmaceutical Company, Ltd., Tokyo, Japan.