PrpE, a PPP protein phosphatase from Bacillus subtilis with unusual substrate specificity

Publisher Website
Google Scholar
Abstract
Bacillus subtilis is a Gram-positive bacterium with a relatively large number of protein phosphatases. Previous studies have shown that some Ser/Thr phosphatases play an important role in the life cycle of this bacterium [Losick and Stragier (1992) Nature (London) 355, 601—604; Yang, Kang, Brody and Price (1996) Genes Dev. 10, 2265—2275]. In this paper, we report the biochemical properties of a putative, previously uncharacterized phosphatase, PrpE, belonging to the PPP family. This enzyme shares homology with other PPP phosphatases as well as with symmetrical diadenosine tetraphosphatases related to ApaH (symmetrical Ap4A hydrolase) from Escherichia coli. A His-tagged recombinant PrpE was purified from E. coli and shown to have Ni2+-dependent and okadaic acid-resistant phosphatase activity against a synthetic phosphorylated peptide and hydrolase activity against diadenosine 5′,5′′′-tetraphosphate. Unexpectedly, PrpE was able to remove phosphate from phosphotyrosine, but not from phosphothreonine or phosphoserine.