Conserved sequence pattern in a wide variety of phosphoesterases.

A unique sequence pattern, designated the GD/GNH signature, was shown to be conserved in a wide variety of phosphoesterases. The enzymes containing this signature cleave phosphoester bonds in such different substrates as (1) phosphoserine and phosphothreonine in polypeptides; (2) bis(5'-nucleosidyl)-tetraphosphates; (3) nucleoside 5' phosphates; (4) 2',3'-cyclic nucleotide phosphates; (5) polynucleotides; (6) 2'-5' phosphodiesters in RNA (intron) lariats; (7) sphingomyelin; and (7) various phosphomonoesters. Two conserved acidic amino acid residues and a conserved histidine residue may be directly involved in phosphoester bond cleavage.