| Popis: |
Computer analysis of a wide range of primary sequences showed that α-, β-, and γ-peptides of membrane-bound methane hydroxylase contained 2, 7, and 6 transmembrane helices respectively. Conservative amino acid residues participating in complex formation were revealed. The α- and γ-peptides are suggested to contain mononuclear copper ions with the ligand environment mainly consisting of His residues. The Cu sites are located in the hydrophilic region and are responsible for ESR signals. The active site of β-peptide in which the activation of O2 and oxidation of CH4 occur is localized in the hydrophobic region close to the membrane surface. This site is formed by the amino acid residues of four transmembrane helices and one loop between them and is suggested to be a binuclear Cu—Fe or Fe—Fe center. The Cu site of α-peptide transfers electrons to the active site of β-peptide, and the Cu site of γ-peptide is either involved in this process or only stabilizes the protein structure. |
Full text from SpringerLink