Mycobacterial adenosine kinase is not a typical adenosine kinase

Adenosine kinase (AK) is only found in eukaryotes. Recently, a Mycobacterium tuberculosis (MTub) protein exhibiting greater sequence similarity to ribokinases (RK) was identified as AK. We have expressed AKs from MTub, human and Chinese hamster (CH) cells in Escherichia coli and also AK from human and MTub in AK-deficient CH cells. While both E. coli and CH cells expressing mammalian AKs efficiently metabolized various adenosine analogs, those …