2cfa
From Proteopedia
STRUCTURE OF VIRAL FLAVIN-DEPENDANT THYMIDYLATE SYNTHASE THYX
Overview
By using biochemical and structural analyses, we have investigated the catalytic mechanism of the recently discovered flavin-dependent thymidylate synthase ThyX from Paramecium bursaria chlorella virus-1 (PBCV-1). Site-directed mutagenesis experiments have identified several residues implicated in either NADPH oxidation or deprotonation activity of PBCV-1 ThyX. Chemical modification by diethyl pyrocarbonate and mass spectroscopic analyses identified a histidine residue (His53) crucial for NADPH oxidation and located in the vicinity of the redox active N-5 atom of the FAD ring system. Moreover, we observed that the conformation of active site key residues of PBCV-1 ThyX differs from earlier reported ThyX structures, suggesting structural changes during catalysis. Steady-state kinetic analyses support a reaction mechanism where ThyX catalysis proceeds via formation of distinct ternary complexes without formation of a methyl enzyme intermediate.
About this Structure
2CFA is a Protein complex structure of sequences from Paramecium bursaria chlorella virus 1. Full crystallographic information is available from OCA.
Reference
Catalytic mechanism and structure of viral flavin-dependent thymidylate synthase ThyX., Graziani S, Bernauer J, Skouloubris S, Graille M, Zhou CZ, Marchand C, Decottignies P, van Tilbeurgh H, Myllykallio H, Liebl U, J Biol Chem. 2006 Aug 18;281(33):24048-57. Epub 2006 May 17. PMID:16707489 Page seeded by OCA on Sat May 3 21:59:40 2008
Categories: Paramecium bursaria chlorella virus 1 | Protein complex | Bernauer, J. | Decottignies, P. | Graille, M. | Graziani, S. | Liebl, U. | Marchand, C. | Myllykallio, H. | Skouloubris, S. | Tilbeurgh, H Van. | Zhou, C Z. | Fdt | Flavin dependent thymidylate synthase fad | Flavoprotein | Methyltransferase | Nucleotide biosynthesis | Paramecium bursaria chlorella virus-1 | Thyx | Transferase | Tscp
