X-ray Crystal Structures of Methane Monooxygenase Hydroxylase Complexes with Variants of Its Regulatory Component: Correlations with Altered Reaction Cycle Dynamics.

ABSTRACT: Full activity of soluble methane monooxygenase (sMMO) depends upon the formation of a 1:1 complex of the regulatory protein MMOB with each alpha subunit of the (αβγ)₂ hydroxylase, sMMOH. Previous studies have shown that mutations in the core region of MMOB and in the N- and C-termini cause dramatic changes in the rate constants for steps in the sMMOH reaction cycle. Here, X-ray crystal structures are reported for the sMMOH complex with two double variants within the core region of MMOB, DBL1 (N107G/S110A), and DBL2 (S109A/T111A), as well as two variants in the MMOB N-terminal region, H33A and H5A. DBL1 causes a 150-fold decrease in the formation rate constant of the reaction cycle intermediate P, whereas DBL2 accelerates the reaction of the dinuclear Fe(IV) intermediate <

SUBMITTER: Jones JC 

PROVIDER: S-EPMC8727504 | biostudies-literature | 2022 Jan

REPOSITORIES: biostudies-literature