title: Evolutionary changes in the fungal carbamoyl-phosphate synthetase small subunit gene and its associated upstream open reading frame.
abstract: The Neurospora crassa arg-2 and the Saccharomyces cerevisiae ortholog CPA1 encode the arginine-specific carbamoyl-phosphate synthetase (CPS-A) small subunit. Arginine decreases synthesis of this subunit through the action of a 5' upstream open reading frame in the mRNA that encodes a cis-regulatory element, the arginine attenuator peptide (AAP), which stalls ribosomes in response to arginine. We performed a comparative analysis of the genomic structure and predicted peptide sequence of the AAP and CPS-A small subunit across many fungi. Differences at the genomic level included variation in intron number and position within the AAP and CPS-A coding regions and differences in known regulatory motifs. Although differences exist in AAP sequence, there were three absolutely conserved amino acid residues in the predicted peptide, including an aspartic acid crucial for arginine-dependent regulation of arg-2 and CPA1. A diverged Basidiomycete AAP was shown to retain function as an Arg-specific negative regulator of translation.
authors.affiliation: Department of Environmental and Biomolecular Systems, Oregon Health & Science University, Beaverton, OR 97006-8921, USA.
authors.forename: Heather M
authors.initials: HM
authors.lastname: Hood
authors.forename: Christina C
authors.initials: CC
authors.lastname: Spevak
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Sachs
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001203:Ascomycota / Q000201:enzymology / Q000235:genetics*; D001487:Basidiomycota / Q000201:enzymology / Q000235:genetics*; D019733:Carbon-Nitrogen Ligases with Glutamine as Amide-N-Donor / Q000235:genetics*; D019143:Evolution, Molecular; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010802:Phylogeny; D021122:Protein Subunits; D016415:Sequence Alignment
chemical_list: D021122:Protein Subunits; D019733:Carbon-Nitrogen Ligases with Glutamine as Amide-N-Donor; C064716:carbamoyl phosphate synthetase (arginine-specific)