Structural Studies of the Methylosinus trichosporium OB3b Soluble Methane Monooxygenase Hydroxylase and Regulatory Component Complex Reveal a Transient Substrate Tunnel.

ABSTRACT: The metalloenzyme soluble methane monooxygenase (sMMO) consists of hydroxylase (sMMOH), regulatory (MMOB), and reductase components. When sMMOH forms a complex with MMOB, the rate constants are greatly increased for the sequential access of O₂, protons, and CH₄ to an oxygen-bridged diferrous metal cluster located in the buried active site. Here, we report high-resolution X-ray crystal structures of the diferric and diferrous states of both sMMOH and the sMMOH:MMOB complex using the components from Methylosinus trichosporium OB3b. These structures are analyzed for O₂ access routes enhanced when the complex forms. Previously reported, lower-resolution structures of the sMMOH:MMOB complex from the sMMO of Methylococcus capsulatus Bath revealed a

SUBMITTER: Jones JC 

PROVIDER: S-EPMC7457393 | biostudies-literature | 2020 Aug

REPOSITORIES: biostudies-literature