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/thr eonine family I phosphatase genes were identified in five strains of c yanobacteria from three species. The gene for one of these protein pho sphatase PCR products, pp1-cyano2 from Microcystis aeruginosa UTEX 206 3, was cloned and sequenced. The deduced protein sequence PP1-cyano2 c ontains 264 amino acid residues (similar to 30.3 kDa). In its N-termin al region, PP1-cyano2 had a GDXXHG(X)(n)GDXXDRG(X)(n)GNHE (n approxima te to 23) sequence that is well-conserved in all protein serine/threon ine family I phosphatases. Of 19 amino acid residues important for eit her metal binding, structure of the active site, or catalysis in eukar yotic PPI, 18 were present in PP1-cyano2. Reverse-transcription-PCR re sults showed that pp1-cyano2 was expressed under laboratory culture co nditions.