Study of three proteins in uracil catabolism pathway

This study focused on expression, purification and functional characterization of three key proteins (Urc1p, Urc2p and Urc8p) in the newly discovered uracil catabolism (URC) pathway. A novel expression system was established by using Saccharomyces kluyveri as a host organism for expression of 6-His tagged Urc1p and Urc2p. Moreover, URC8 gene was cloned in pET151/D-TOPO vector and expressed in Escherichia coli. All three recombined proteins were purified on nickel columns. The SDS-PAGE showed Urc1p and Urc8p are of correct size and high purity. This novel expression system provides an alternative or a complementary choice for eukaryotic protein production. The functional characterization assay suggested that Urc1p might open the pyrimidine ring of uridine in the URC pathway and Urc8p is a NADPH dependent reductase converting malonic semialdehyde to 3-hydroxypropionate, which is one of the final products in the URC pathway