The bifunctional dihydrofolate reductase thymidylate synthase of Tetrahymena thermophila provides a tool for molecular and biotechnology applications

A bifunctional thymidylate synthetase-dihydrofolate reductase in protozoa.

Thymidylate synthetase and dihydrofolate reductase exist as a bifunctional protein in a number of species of protozoa which span diverse groups of the subkingdom. The enzymes copurify upon gel filtration and on affinity chromatography columns specific for dihydrofolate reductase. The bifunctional protein has been found in species of Crithidia, Leishmania, Trypanosoma, Plasmodium, Eimeria, Tetra...

Phylogenetic classification of protozoa based on the structure of the linker domain in the bifunctional enzyme, dihydrofolate reductase-thymidylate synthase.

We have determined the crystal structure of dihydrofolate reductase-thymidylate synthase (DHFR-TS) from Cryptosporidium hominis, revealing a unique linker domain containing an 11-residue alpha-helix that has extensive interactions with the opposite DHFR-TS monomer of the homodimeric enzyme. Analysis of the structure of DHFR-TS from C. hominis and of previously solved structures of DHFR-TS from ...

A molecular docking strategy identifies Eosin B as a non-active site inhibitor of protozoal bifunctional thymidylate synthase-dihydrofolate reductase.

Protozoal parasites are unusual in that their thymidylate synthase (TS) and dihydrofolate reductase (DHFR) enzymes exist on a single polypeptide. In an effort to probe the possibility of substrate channeling between the TS and DHFR active sites and to identify inhibitors specific for bifunctional TS-DHFR, we used molecular docking to screen for inhibitors targeting the shallow groove connecting...

Construction of a homodimeric dihydrofolate reductase-thymidylate synthase bifunctional enzyme.

A gene encoding a bifunctional homodimeric dihydrofolate reductase-thymidylate synthase (DHFR-TS) was constructed by destroying the stop codon of Escherichia coli dihydrofolate reductase (DHFR) and joining the coding sequences of the monofunctional enzymes by a five amino acid linker. The protein was designed to mimic features of active site proximity and electrostatics in the protozoan DHFR-TS...

The crystal structure of dihydrofolate reductase-thymidylate synthase from Cryptosporidium hominis reveals a novel architecture for the bifunctional enzyme.