Conserved sequence pattern in a wide variety of phosphoesterases

Abstract 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′ phospho‐diesters 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.