3ab9

Crystal Structure of lipoylated E. coli H-protein (reduced form)

spinqualitylabelsall models 3ab9, resolution 1.65Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3ab9 is a 1 chain structure with sequence from Escherichia coli K-12. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.65Å Ligands: CA, CL, LA2 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function GCSH_ECOLI The glycine cleavage system catalyzes the degradation of glycine. The H protein shuttles the methylamine group of glycine from the P protein to the T protein.[HAMAP-Rule:MF_00272] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed 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 dihydrolipoyllysine arm inserted into the active site cavity of the T-protein. Invariant Arg(292) of the T-protein is essential for complex assembly. The structure also provides novel insights in understanding the disease-causing mutations, in addition to the disease-related impairment in the cofactor-enzyme interactions reported previously. Furthermore, structural and mutational analyses suggest that the reversible transfer of the methylene group between the lipoate and tetrahydrofolate should proceed through the electron relay-assisted iminium intermediate formation. 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.,Okamura-Ikeda K, Hosaka H, Maita N, Fujiwara K, Yoshizawa AC, Nakagawa A, Taniguchi H J Biol Chem. 2010 Jun 11;285(24):18684-92. Epub 2010 Apr 6. PMID:20375021 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

Proteopedia Page Contributors and Editors (what is this?)

OCA