Solution structure of thermostable cytochrome c-552 from Hydrogenobacter thermophilus determined by 1H-NMR spectroscopy.
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.
Hasegawa
J
J
Daiichi Pharmaceutical Company, Ltd., Tokyo, Japan.
Yoshida
T
T
Yamazaki
T
T
Sambongi
Y
Y
Yu
Y
Y
Igarashi
Y
Y
Kodama
T
T
Yamazaki
K
K
Kyogoku
Y
Y
Kobayashi
Y
Y
D000595:Amino Acid Sequence; D001120:Arginine / Q000737:chemistry; D001420:Bacteria, Aerobic / Q000201:enzymology*; D001426:Bacterial Proteins; D018360:Crystallography, X-Ray; D003574:Cytochrome c Group / Q000737:chemistry*; D006418:Heme / Q000737:chemistry; D006860:Hydrogen Bonding; D008239:Lysine / Q000737:chemistry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D010455:Peptides / Q000737:chemistry; D011487:Protein Conformation; D017510:Protein Folding; D011522:Protons; D011550:Pseudomonas aeruginosa / Q000201:enzymology; D017386:Sequence Homology, Amino Acid; D012996:Solutions; D013816:Thermodynamics; D014443:Tyrosine / Q000737:chemistry
D001426:Bacterial Proteins; D003574:Cytochrome c Group; D010455:Peptides; D011522:Protons; D012996:Solutions; C083951:cytochrome c553; D014443:Tyrosine; D006418:Heme; C017167:cytochrome C(551); C022302:cytochrome C-552; D001120:Arginine; D008239:Lysine