3.1.1.89 K38A mutation does not abolish nuclear localization of enzyme 714919 3.1.1.89 additional information construction of deletion mutants and expression in HeLa cells. Domain 1 of the enzyme extends from amino acids 1 to 233, domain 2 from amino acids 234 to 284 and domain 3 includes amino acids 285 to 378. Domain 1 of PME-1 does not migrate into the nucleus and domain 3 shows a speckled cytoplasmic distribution, whereas domain 2 is targeted to the nucleus 714919 3.1.1.89 R271A mutation abolishes nuclear localization of enzyme 714919 3.1.1.89 R37A mutation does not abolish nuclear localization of enzyme 714919 3.1.1.89 R39A mutation does not abolish nuclear localization of enzyme 714919 3.1.1.89 S156A mutation abolishes the methylesterase activity, residue S156 is a functional active site serine 714919