Biochemical characterization of Pkn2, a protein Ser/Thr kinase from Myxococcus xanthus, a Gram‐negative developmental bacterium

摘要

>Pkn2, a protein Ser/Thr kinase, from the developmental bacterium Myxococcus xanthus was expressed under a T7 promoter in Escherichia coli and purified. Purified Pkn2 retained the autophosphorylation activity with the K _m value of 177 μM for ATP and 73 nmol/min/mg for V _max. The optimum pH and temperature were determined to be 7.5 and 35°C, respectively. The autophosphorylation activity was inhibited by staurosporine with the IC₅₀ value of 400 nM while H-7 and genistein had little effect on this kinase. Pkn2 appears to be unique for its higher manganese dependence. This is the first biochemical characterization of the prokaryotic protein Ser/Thr kinase.