Cg0063 is phosphorylated in vitro by PknA and PknL in C. glutamicum. All four Ser/Thr Pkn kinases from C. glutamicum (PknA/B/L/G) and Cg0063 have been expressed and purified as described previously [105]. Then, Cg0063 was incubated alone or with the different Pkn kinases in the presence of [γ-33P] ATP for 30 min. Samples were separated by SDS-PAGE electrophoresis and stained with Coomassie Blue (upper panel) or visualized by autoradiography (lower panel). PknA/B/L kinases exhibit an autophosphorylation activity, whereas Cg0063 is mostly phosphorylated by PknA and PknL. M. Fiuza, unpublished results.
