pp1-cyano2, a protein serine/threonine phosphatase 1 gene from the cyanobacterium Microcystis aeruginosa UTEX 2063

Polymerase chain reaction (PCR) products similar to protein serine/threonine family I phosphatase genes were identified in five strains of cyanobacteria from three species. The gene for one of these protein phosphatase PCR products, pp1-cyano2 from Microcystis aeruginosa UTEX 2063, was cloned and sequenced. The deduced protein sequence PP1-cyano2 contains 264 amino acid residues (similar to 30.3 kDa). In its N-terminal region, PP1-cyano2 had a GDXXHG(X)(n)GDXXDRG(X)(n)GNHE (n approximate to 23) sequence that is well-conserved in all protein serine/threonine family I phosphatases. Of 19 amino acid residues important for either metal binding, structure of the active site, or catalysis in eukaryotic PPI, 18 were present in PP1-cyano2. Reverse-transcription-PCR results showed that pp1-cyano2 was expressed under laboratory culture conditions.