mycothiol biosynthesis starts from Ins-1-P not Ins Ralf Stephan, none 20 August 2010 The authors claim that inositol and thus, Ins-P phosphatase avtivity, is necessary for mycothiol biosynthesis in M. tuberculosis. This is not the case. In short, mycothiol biosynthesis appears to start from inositol-1-phosphate, not inositol, thus doing away with the claimed need for IMPase in mycothiol biosynthesis because inositol-1-phosphate is readily made from glucose-6-phosphate, catalyzed by Ino1. Reference: G. L. Newton, P. Ta, K. P. Bzymek, and R. C. Fahey. Biochemistry of the initial steps of mycothiol biosynthesis. J Biol Chem, 281(45):33910–20, Nov 2006. PMID 16940050 Regards, Ralf Stephan Librarian, currently working on bioinformatics annotation of M.tb. Competing interests None.