title: A subfamily of PLP-dependent enzymes specialized in handling terminal amines.
abstract: The present review focuses on a subfamily of pyridoxal phosphate (PLP)-dependent enzymes, belonging to the broader fold-type I structural group and whose archetypes can be considered ornithine δ-transaminase and γ-aminobutyrate transaminase. These proteins were originally christened "subgroup-II aminotransferases" (AT-II) but are very often referred to as "class-III aminotransferases". As names suggest, the subgroup includes mainly transaminases, with just a few interesting exceptions. However, at variance with most other PLP-dependent enzymes, catalysts in this subfamily seem specialized at utilizing substrates whose amino function is not adjacent to a carboxylate group. AT-II enzymes are widespread in biology and play mostly catabolic roles. Furthermore, today several transaminases in this group are being used as bioorganic tools for the asymmetric synthesis of chiral amines. We present an overview of the biochemical and structural features of these enzymes, illustrating how they are distinctive and how they compare with those of the other fold-type I enzymes. This article is part of a Special Issue entitled: Cofactor-dependent proteins: evolution, chemical diversity and bio-applications.
authors.affiliation: Department of Life Sciences, Laboratory of Biochemistry, Molecular Biology and Bioinformatics, University of Parma, 43124 Parma, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Schiroli
authors.affiliation: Department of Life Sciences, Laboratory of Biochemistry, Molecular Biology and Bioinformatics, University of Parma, 43124 Parma, Italy. Electronic address: alessio.peracchi@unipr.it.
authors.forename: Alessio
authors.initials: A
authors.lastname: Peracchi
mesh_terms: D000588:Amines / Q000378:metabolism*; D001665:Binding Sites; D002384:Catalysis; D011732:Pyridoxal Phosphate / Q000502:physiology*; D013379:Substrate Specificity; D000637:Transaminases / Q000737:chemistry / Q000378:metabolism*
chemical_list: D000588:Amines; D011732:Pyridoxal Phosphate; D000637:Transaminases
keywords: Dual-specificity; Evolution of enzyme families; Pyridoxal-phosphate; ω-Aminotransferases