The nonconserved N-terminus of protein phosphatases 1 influences its active site

at the carboxyl terminus. The nonconserved N-termi-nus amino acids residues are shown. The conserved core is com-posed of 10α helices and 14β strands. The hydrophobic groove, C-terminal groove, and acidic groove converge at the active site, which contains two metal ions (designated M1 and M2). OA is shown in a ball-and-stick form with carbon atoms in yellow and oxygen atoms in red. (reproduced from Fig. 1A of reference 6).