Conformational switching and flexibility in cobalamin-dependent methionine synthase studied by small-angle X-ray scattering and cryoelectron microscopy.

ABSTRACT: Cobalamin-dependent methionine synthase (MetH) catalyzes the synthesis of methionine from homocysteine and 5-methyltetrahydrofolate (CH₃-H₄folate) using the unique chemistry of its cofactor. In doing so, MetH links the cycling of S-adenosylmethionine with the folate cycle in one-carbon metabolism. Extensive biochemical and structural studies on Escherichia coli MetH have shown that this flexible, multidomain enzyme adopts two major conformations to prevent a futile cycle of methionine production and consumption. However, as MetH is highly dynamic as well as both a photosensitive and oxygen-sensitive metalloenzyme, it poses special challenges for structural studies, and existing structures have necessarily come from a "divide and conquer" approach. In thi

SUBMITTER: Watkins MB 

PROVIDER: S-EPMC10293825 | biostudies-literature | 2023 Jun

REPOSITORIES: biostudies-literature