Diiron oxidation state control of substrate access to the active site of soluble methane monooxygenase mediated by the regulatory component.

ABSTRACT: The regulatory component (MMOB) of soluble methane monooxygenase (sMMO) has a unique N-terminal tail not found in regulatory proteins of other bacterial multicomponent monooxygenases. This N-terminal tail is indispensable for proper function, yet its solution structure and role in catalysis remain elusive. Here, by using double electron-electron resonance (DEER) spectroscopy, we show that the oxidation state of the hydroxylase component, MMOH, modulates the conformation of the N-terminal tail in the MMOH-2MMOB complex, which in turn facilitates catalysis. The results reveal that the N-terminal tail switches from a relaxed, flexible conformational state to an ordered state upon MMOH reduction from the diiron(III) to the diiron(II) state. This observation suggests that some of the crystallog

SUBMITTER: Wang W 

PROVIDER: S-EPMC3954536 | biostudies-literature | 2014 Feb

REPOSITORIES: biostudies-literature