Crystal structure of aminomethyltransferase in complex with dihydrolipoyl-H-protein of the glycine cleavage system: implications for recognition of lipoyl protein substrate, disease-related mutations, and reaction mechanism.

ABSTRACT: Aminomethyltransferase, a component of the glycine cleavage system termed T-protein, reversibly catalyzes the degradation of the aminomethyl moiety of glycine attached to the lipoate cofactor of H-protein, resulting in the production of ammonia, 5,10-methylenetetrahydrofolate, and dihydrolipoate-bearing H-protein in the presence of tetrahydrofolate. Several mutations in the human T-protein gene are known to cause nonketotic hyperglycinemia. Here, we report the crystal structure of Escherichia coli T-protein in complex with dihydrolipoate-bearing H-protein and 5-methyltetrahydrofolate, a complex mimicking the ternary complex in the reverse reaction. The structure of the complex shows a highly interacting intermolecular interface limited to a small area and the protein-bound dihydrolipoyllys

SUBMITTER: Okamura-Ikeda K 

PROVIDER: S-EPMC2881793 | biostudies-literature | 2010 Jun

REPOSITORIES: biostudies-literature