{PDOC00086} {PS00091; THYMIDYLATE_SYNTHASE} {BEGIN} ************************************ * Thymidylate synthase active site * ************************************ Thymidylate synthase (EC 2.1.1.45) [1,2] catalyzes the reductive methylation of dUMP to dTMP with concomitant conversion of 5,10-methylenetetrahydrofolate to dihydrofolate. Thymidylate synthase plays an essential role in DNA synthesis and is an important target for certain chemotherapeutic drugs. Thymidylate synthase is an enzyme of about 30 to 35 Kd in most species except in protozoan and plants where it exists as a bifunctional enzyme that includes a dihydrofolate reductase domain. A cysteine residue is involved in the catalytic mechanism (it covalently binds the 5,6-dihydro-dUMP intermediate). The sequence around the active site of this enzyme is conserved from phages to vertebrates. -Consensus pattern: R-x(2)-[LIVMT]-x(2,3)-[FWY]-[QNYDI]-x(8,13)-[LVESI]-x-P-C- [HAVMLC]-x(3)-[QMTLHD]-[FYWL]-x(0,1)-[LV] [C is the active site residue] -Sequences known to belong to this class detected by the pattern: ALL. -Other sequence(s) detected in Swiss-Prot: NONE. -Last update: December 2004 / Pattern and text revised. [ 1] Benkovic S.J. "On the mechanism of action of folate- and biopterin-requiring enzymes." Annu. Rev. Biochem. 49:227-251(1980). PubMed=6996564; DOI=10.1146/annurev.bi.49.070180.001303 [ 2] Ross P., O'Gara F., Condon S. "Cloning and characterization of the thymidylate synthase gene from Lactococcus lactis subsp. lactis." Appl. Environ. Microbiol. 56:2156-2163(1990). PubMed=2117882 -------------------------------------------------------------------------------- PROSITE is copyrighted by the SIB Swiss Institute of Bioinformatics and distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives (CC BY-NC-ND 4.0) License, see https://prosite.expasy.org/prosite_license.html -------------------------------------------------------------------------------- {END}