title: Independent catalysis of the short form HisG from Lactococcus lactis.
abstract: ATP-phosphoribosyltransferase (ATP-PRT) catalyses the first step of histidine biosynthesis. Two different forms of ATP-PRT have been described; the homo-hexameric long form, and the hetero-octameric short form. Lactococcus lactis possesses the short form ATP-PRT comprising four subunits of HisGS , the catalytic subunit, and four subunits of HisZ, a histidyl-tRNA synthetase paralogue. Previous studies have suggested that HisGS requires HisZ for catalysis. Here, we reveal that the dimeric HisGS does display ATP-PRT activity in the absence of HisZ. This result reflects the evolutionary relationship between the long and short form ATP-PRT, which acquired allosteric inhibition and enhanced catalysis via two divergent strategies.
authors.affiliation: Department of Chemistry and Biomolecular Interaction Centre, University of Canterbury, Christchurch, New Zealand.
authors.forename: Emma K
authors.initials: EK
authors.lastname: Livingstone
authors.affiliation: Department of Chemistry and Biomolecular Interaction Centre, University of Canterbury, Christchurch, New Zealand.
authors.forename: Gerd
authors.initials: G
authors.lastname: Mittelstädt
authors.affiliation: Department of Chemistry and Biomolecular Interaction Centre, University of Canterbury, Christchurch, New Zealand.
authors.forename: Fiona M
authors.initials: FM
authors.lastname: Given
authors.affiliation: Department of Chemistry and Biomolecular Interaction Centre, University of Canterbury, Christchurch, New Zealand.
authors.forename: Emily J
authors.initials: EJ
authors.lastname: Parker
mesh_terms: D001276:ATP Phosphoribosyltransferase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D000604:Amino Acyl-tRNA Synthetases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002384:Catalysis; D020134:Catalytic Domain / Q000235:genetics; D006639:Histidine / Q000737:chemistry / Q000378:metabolism; D013294:Lactococcus lactis / Q000201:enzymology; D009004:Monosaccharide Transport Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; C106638:HisG protein, bacteria; D009004:Monosaccharide Transport Proteins; D020033:Protein Isoforms; D006639:Histidine; D001276:ATP Phosphoribosyltransferase; D000604:Amino Acyl-tRNA Synthetases; C120928:HisZ protein, Lactococcus lactis
keywords: ATP-PRT; HisG; histidine biosynthesis