Mossbauer studies of the membrane-associated methane monooxygenase from Methylococcus capsulatus bath: evidence for a Diiron center.

ABSTRACT: Two methane monooxygenase (MMO) systems have been identified in methanotrophic bacteria, namely, a soluble or cytoplasmic MMO and a membrane-associated or particulate MMO. The active site of the well-characterized soluble MMO contains a bis-mu-hydroxo-bridged diiron cluster. X-ray crystallographic studies of the particulate enzyme, pMMO, have identified two copper centers on the alpha subunit (pmoB) of the alphabetagamma trimer and a site at the interface of the betagamma subunits filled by a Zn, apparently from the crystallization buffer. In our hands, pMMO preparations containing 1-2 iron atoms per alphabetagamma show the highest catalytic activity. We have employed Mössbauer spectroscopy to characterize the iron in our preparations. Interestingly, we find in pMMO a component with the sa

SUBMITTER: Martinho M 

PROVIDER: S-EPMC2533734 | biostudies-literature | 2007 Dec

REPOSITORIES: biostudies-literature