Open AccessStructure and heme environment of beef liver catalase at 2.5 A resolution.
Author(s) -
Thomas Reid,
M.R.N. Murthy,
Andrew Sicignano,
Nobuo Tanaka,
W.Donald L. Musick,
Michael G. Rossmann
Publication year - 1981
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.78.8.4767
Subject(s) - heme , histidine , antiparallel (mathematics) , asparagine , chemistry , stereochemistry , covalent bond , crystallography , peptide sequence , amino acid , ligand (biochemistry) , resolution (logic) , protein structure , hydrogen bond , biochemistry , molecule , enzyme , physics , receptor , organic chemistry , quantum mechanics , artificial intelligence , magnetic field , computer science , gene
Most of the amino acid side chains of beef liver catalase were clearly identifiable in the 2.5 A resolution electron-density map, and the results are in good agreement with the sequence [Schroeder, W. A., Shelton, J. R., Shelton, J. B., Roberson, B. & Apell, G. (1969) Arch. Biochem. Biophys. 131, 653-655]. The tertiary structure of one subunit consists of a large antiparallel beta-pleated sheet domain with helical insertions, followed by a smaller domain containing four alpha-helices. The heme group is buried at least 20 A below the molecular surface and is accessible by a channel lined with hydrophobic residues. The proximal ligand is tyrosine-357, while histidine-74 and asparagine-147 re the important residues on the distal side of the heme. The inhibitor 3-amino-1,2,4-triazole, which has been shown to covalently bond to histidine-74, can be built into the heme cavity with its N(2) atom coordinated to the heme iron.