2CFA

Structure of viral flavin-dependant thymidylate synthase ThyX

Summary for 2CFA

• Entry DOI: 10.2210/pdb2cfa/pdb
• Descriptor: THYMIDYLATE SYNTHASE, FLAVIN-ADENINE DINUCLEOTIDE, ... (4 entities in total)
• Functional Keywords: fdts, tscp, flavin dependent thymidylate synthase fad, flavoprotein, nucleotide biosynthesis, methyltransferase, transferase
• Biological source: PARAMECIUM BURSARIA CHLORELLA VIRUS 1; More
• Total number of polymer chains: 2
• Total formula weight: 51872.35

Authors

Graziani, S.,Bernauer, J.,Skouloubris, S.,Graille, M.,Zhou, C.-Z.,Marchand, C.,Decottignies, P.,van Tilbeurgh, H.,Myllykallio, H.,Liebl, U. (deposition date: 2006-02-17, release date: 2006-05-16, Last modification date: 2023-12-13)

Primary citation

Graziani, S.,Bernauer, J.,Skouloubris, S.,Graille, M.,Zhou, C.-Z.,Marchand, C.,Decottignies, P.,Van Tilbeurgh, H.,Myllykallio, H.,Liebl, U.
Catalytic Mechanism and Structure of Viral Flavin-Dependent Thymidylate Synthase Thyx.
J.Biol.Chem., 281:24048-, 2006

PubMed Abstract: 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.

PubMed: 16707489
DOI: 10.1074/JBC.M600745200

Experimental method

X-RAY DIFFRACTION (2.3 Å)