title: On the origins of esterases.
abstract: Comparisons among the primary sequences of five cloned eukaryotic esterases reveal two distinct lineages, neither bearing any significant overall sequence similarity to the functionally related serine protease multigene family. We have not eliminated the possibility that the esterases may have residual conformational similarities to the serine proteases. However, our profile analysis and analyses of the predicted conformations of the esterases reveal little similarity to the serine proteases. Four of the esterase proteins share 27%-53% overall sequence similarity and evidence of a catalytic mechanism involving the same Arg-Asp-Ser or His-Asp-Ser charge relay. We propose that these four esterases, three of them cholinesterases, form part of a multigene family essentially separate from the serine proteases.
authors.affiliation: CSIRO Division of Entomology, Australian National University.
authors.forename: M
authors.initials: M
authors.lastname: Myers
authors.forename: R C
authors.initials: RC
authors.lastname: Richmond
authors.forename: J G
authors.initials: JG
authors.lastname: Oakeshott
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D005075:Biological Evolution; D002802:Cholinesterases / Q000235:genetics; D004950:Esterases / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D005810:Multigene Family; D011487:Protein Conformation; D012689:Sequence Homology, Nucleic Acid; D012697:Serine Endopeptidases / Q000235:genetics
chemical_list: D004950:Esterases; D002802:Cholinesterases; D012697:Serine Endopeptidases