Abstract
We demonstrate that Mycobacterium tuberculosis GroEL1 is phosphorylated by PknF at two positions, Thr25 and Thr54. Unexpectedly, Mycobacterium smegmatis GroEL1 is not a substrate of its cognate PknF. This study shows that the phosphorylation profiles of conserved proteins are species dependent and provide insights that may explain the numerous biological functions of these important proteins.