Disease relevance of thyA

• This open reading frame is immediately 5' to the thyA gene and is allelic to umpA of Escherichia coli [1].
• Bacillus subtilis strain 168 is known to possess two genes that encode thymidylate synthases, thyA and thyB [2].
• Analysis of thyA genes cloned from B. subtilis W23 strain 2A6, B. subtilis ATCC6633, B. amyloliquefaciens S18 and B. atrophaeus S223 reveals that they are very similar to the thyA genes from B. subtilis 168 and its phage phi3T, but differ considerably from the majority of known prokaryotic and eukaryotic thymidylate synthases [2].
• This method was applied to generate a potent inhibitor for thymidylate synthase, an essential enzyme in pyrimidine metabolism with therapeutic applications in cancer and infectious diseases [3].
• However, the development of potent cofactor analog inhibitors of TS, such as CB3717, as drugs has been slowed by their toxicity, which often becomes apparent as hepatic and renal toxicity mediated by the specific chemistry of the compound [4].

High impact information on thyA

• Inactivity of N229A thymidylate synthase due to water-mediated effects: isolating a late stage in methyl transfer [5].
• Mutation of thymidylate synthase N229(177) to alanine results in an essentially inactive enzyme, yet it leads to formation of a stable ternary complex [5].
• The enzyme thymidylate synthase (TS) catalyzes the reductive methylation of 2'-deoxyuridine 5'-monophosphate (dUMP) to 2'-deoxythymidine 5'-monophosphate [6].
• The role of protein dynamics in thymidylate synthase catalysis: variants of conserved 2'-deoxyuridine 5'-monophosphate (dUMP)-binding Tyr-261 [6].
• The structure also provides insight into the role of specific waters in the active site which have been suggested to be important in the TS reaction [7].

Chemical compound and disease context of thyA

• We have addressed the role of glutamate 60(58) in the TS reaction by cocrystalizing the Escherichia coli TS mutant E60(58)Q with dUMP and the cofactor analog CB3717 and have determined the X-ray crystal structure to 2.5 A resolution with a final R factor of 15.2% (Rfree = 24.0%) [7].
• The structure of a polyglutamyl cofactor analog bound in ternary complex with deoxyuridine monophosphate (dUMP) and Escherichia coli TS reveals how the polyglutamyl moiety is positioned in TS and accounts in a qualitative way for the binding contributions of the different individual glutamate residues [8].
• Binding of the anticancer drug ZD1694 to E. coli thymidylate synthase: assessing specificity and affinity [4].
• Tyr94 of Escherichia coli thymidylate synthase is thought to be involved, either directly or by activation of a water molecule, in the abstraction of a proton from C5 of the 2'-deoxyuridine 5'-monophosphate (dUMP) substrate [9].

Biological context of thyA

• Structure, multiple site binding, and segmental accommodation in thymidylate synthase on binding dUMP and an anti-folate [10].
• Finally, the structure shows a unique conformation for the cofactor analog, CB3717, which has implications for structure-based drug design and sheds light on the controversy surrounding the previously observed enzymatic nonidentity between the chemically identical monomers of the TS dimer [7].
• Thymidylate synthase (TS) converts dUMP to dTMP by reductive methylation, where 5,10-methylenetetrahydrofolate is the source of both the methylene group and reducing equivalents [11].
• Amino acid substitution analysis of E. coli thymidylate synthase: the study of a highly conserved region at the N-terminus [12].
• Nucleotide sequence of the thymidylate synthase B and dihydrofolate reductase genes contained in one Bacillus subtilis operon [13].

Associations of thyA with chemical compounds

• The X-ray crystal structure of the product complex of thymidylate synthase (1.83-A resolution, R factor = 0.183 for all data between 7.0 and 1.83 A) identifies a bound water molecule that serves to disfavor binding of the product nucleotide, dTMP [14].
• A water-mediated hydrogen bond network coordinated by glutamate 60(58) appears to play an important role in the thymidylate synthase (TS) reaction mechanism [7].
• Thymidylate synthase (TS) catalyzes the final step in the de novo synthesis of thymidine [8].
• In ThyA TS, the active site histidine is replaced by valine [11].
• CONCLUSIONS: The binding mode of ZD1694 to thymidylate synthase has been determined at atomic resolution [4].

Regulatory relationships of thyA

• Thymidylate synthase levels are regulated by transcription from the lgt promoter and by translational coupling [15].

Analytical, diagnostic and therapeutic context of thyA

• The localization of SeqA, thymidylate synthase, DnaB (helicase) and the DNA polymerase components alpha and tau, has been studied by immunofluorescence microscopy [16].
• Using kinetic and X-ray crystallography experiments, we have examined the role of the highly conserved Tyr-261 in the catalytic mechanism of TS [6].
• Western immunoblot assay confirmed that TS was expressed in all the developmental stages of zebrafish with a high level of expression at the 1-4 cell stages [17].
• Sequence analysis and functional study of thymidylate synthase from zebrafish, Danio rerio [17].
• In order to use zebrafish as an animal model for screening novel anticancer agents, we isolated TS cDNA from zebrafish and compared its sequence with those from other species [17].

References