Spectrophotometric Assays to Quantify the Activity of T4SS ATPases

Biogenesis of T4SS apparatus and substrate transport require energy. Conjugative T4SS have three ATPases that enable DNA processing and transport of the nucleoprotein complex to the recipient cell. In the conjugative plasmid R388, these ATPases are named TrwB, TrwK, and TrwD. Here, three different spectrophotometric assays to measure the enzymatic properties of these ATPases are described. The choice of the assay will depend on the specific requirements of each enzyme.