Dear All: Thanks for all your replies to this. Phosphorylation is possible in E. coli. One article of particular interest is Mol Cell Proteomics 2007 Eprint by Macek B, Gnad, F, Soufu B, Kumar C, Olsen JV, Mijakovic, I and Mann M.
Many others have pointed out that it is possible and many likely residues such as Asp, Thr/Ser, His and Tyr are candidates for phosphorylation. To those who wanted to know whether the protein I am working on is a kinase: No, it is not. Thank you all again Subbu
