title: Allosteric ACTion: the varied ACT domains regulating enzymes of amino-acid metabolism.
abstract: Allosteric regulation of enzyme activity plays important metabolic roles. Here we review the allostery of enzymes of amino-acid metabolism conferred by a discrete domain known as the ACT domain. This domain of 60-70 residues has a βαββαβ topology leading to a four-stranded β4β1β3β2 antiparallel sheet with two antiparallel helices on one face. Extensive sequence variation requires a combined sequence/structure/function analysis for identification of the ACT domain. Common features include highly varied modes of self-association of ACT domains, ligand binding at domain interfaces, and transmittal of allosteric signals through conformational changes and/or the manipulation of quaternary equilibria. A recent example illustrates the relatively facile adoption of this versatile module of allostery by gene fusion.
authors.affiliation: Maurice Wilkins Centre, Biomolecular Interaction Centre, Department of Chemistry, University of Canterbury, Christchurch, New Zealand.
authors.forename: Eric J M
authors.initials: EJ
authors.lastname: Lang
authors.affiliation: Maurice Wilkins Centre, Biomolecular Interaction Centre, Department of Chemistry, University of Canterbury, Christchurch, New Zealand.
authors.forename: Penelope J
authors.initials: PJ
authors.lastname: Cross
authors.affiliation: Maurice Wilkins Centre, Biomolecular Interaction Centre, Department of Chemistry, University of Canterbury, Christchurch, New Zealand.
authors.forename: Gerd
authors.initials: G
authors.lastname: Mittelstädt
authors.affiliation: Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand.
authors.forename: Geoffrey B
authors.initials: GB
authors.lastname: Jameson
authors.affiliation: Maurice Wilkins Centre, Biomolecular Interaction Centre, Department of Chemistry, University of Canterbury, Christchurch, New Zealand. Electronic address: emily.parker@canterbury.ac.nz.
authors.forename: Emily J
authors.initials: EJ
authors.lastname: Parker
mesh_terms: D000494:Allosteric Regulation; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism; D001665:Binding Sites; D004926:Escherichia coli / Q000201:enzymology; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation
chemical_list: D000596:Amino Acids; D001426:Bacterial Proteins