title: Evolution of transcription-regulating proteins by enzyme recruitment: molecular models for nitrogen metabolite repression and ethanol utilisation in eukaryotes.
abstract: Studies on the quinic acid utilisation gene (qut) cluster in Aspergillus nidulans showed that the genes encoding transcriptional activator and repressor proteins evolved by co-opting duplicated copies of genes encoding metabolic enzymes. In order to test the hypothesis that this was a general route for the genesis of regulatory proteins, the origins of the major control protein mediating nitrogen metabolite repression (an example of inter-pathway regulation) and ethanol utilisation (an example of intra-pathway regulation) in filamentous fungi were sought. The regulatory proteins mediating nitrogen metabolite repression were deduced to have originated in a duplication of genes encoding the anthranilate synthase complex which is active in the shikimate pathway. The major protein regulating ethanol utilisation was deduced to have its origin in the fusion of duplicated genes encoding the aldehyde and alcohol dehydrogenases (ALDA and ALCA). These data strongly support the view that transcriptional regulatory proteins evolve by the recruitment of functional domains provided by metabolic enzymes.
authors.affiliation: Department of Biochemistry and Genetics, Medical School, University of Newcastle upon Tyne, UK.
authors.forename: A R
authors.initials: AR
authors.lastname: Hawkins
authors.forename: H K
authors.initials: HK
authors.lastname: Lamb
authors.forename: A
authors.initials: A
authors.lastname: Radford
authors.forename: J D
authors.initials: JD
authors.lastname: Moore
mesh_terms: D001233:Aspergillus nidulans / Q000235:genetics* / Q000378:metabolism; D005075:Biological Evolution; D017124:Conserved Sequence / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000502:physiology; D000431:Ethanol / Q000378:metabolism*; D005656:Fungal Proteins / Q000235:genetics* / Q000502:physiology; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal / Q000235:genetics*; D005809:Genes, Regulator / Q000235:genetics*; D005973:Glutamine / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D009492:Neurospora crassa / Q000235:genetics* / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism*; D000644:Quaternary Ammonium Compounds / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics*; D014158:Transcription, Genetic / Q000235:genetics*
chemical_list: C074202:ALCR protein, Aspergillus nidulans; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D000644:Quaternary Ammonium Compounds; D014157:Transcription Factors; D005973:Glutamine; D000431:Ethanol; D009584:Nitrogen