2v9y

Publication Abstract from PubMed

Human purine de novo synthesis pathway contains several multi-functional enzymes, one of which, tri-functional GART, contains three enzymatic activities in a single polypeptide chain. We have solved structures of two domains bearing separate catalytic functions: glycinamide ribonucleotide synthetase and aminoimidazole ribonucleotide synthetase. Structures are compared with those of homologous enzymes from prokaryotes and analyzed in terms of the catalytic mechanism. We also report small angle X-ray scattering models for the full-length protein. These models are consistent with the enzyme forming a dimer through the middle domain. The protein has an approximate seesaw geometry where terminal enzyme units display high mobility owing to flexible linker segments. This resilient seesaw shape may facilitate internal substrate/product transfer or forwarding to other enzymes in the pathway.

Structural studies of tri-functional human GART.,Welin M, Grossmann JG, Flodin S, Nyman T, Stenmark P, Tresaugues L, Kotenyova T, Johansson I, Nordlund P, Lehtio L Nucleic Acids Res. 2010 Nov 1;38(20):7308-19. Epub 2010 Jul 14. PMID:20631005^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.