Functional assignment of uncharacterized enzymes

The sequencing of numerous bacterial genomes has led to the identification of a large number of unknown genes. The functional assignment of proteins encoded by these genes is an inherently difficult but important task for molecular biology. In particular, the discovery of novel enzymes will provide insights into unknown parts of cellular metabolism and into the molecular evolution of proteins.

We want to contribute to enzyme discovery by investigating the enzymes TrpB2 and PcrB. These two proteins show similarities in structure and sequence to two well characterised enzymes from histidine and tryptophan biosynthesis (HisF and TrpB1), but have a different and hitherto unknown function. Both TrpB2 and PcrB have two substrates, one of which is known and one is unknown. Using various biochemical approaches, we want to identify the products of the reactions, which will allow us to identify the unknown second substrates. These studies will be complemented by the phenotypic analysis of two knock-out strains lacking pcrB or trpB2o on their genomes.