title: Sequence analysis of the pyr-4 (orotidine 5'-P decarboxylase) gene of Neurospora crassa.
abstract: The pyr-4 gene of Neurospora crassa encodes orotidine-5' -phosphate decarboxylase, which catalyses the sixth step in the pyrimidine biosynthetic pathway. The complete nucleotide sequence of a 1.8-kb genomic fragment containing the pyr-4 gene has been determined. Using transposon mutagenesis, the coding region has been identified, and the amino acid (aa) sequence deduced. Comparison of the pyr-4 aa sequence with URA3, the equivalent gene of Saccharomyces cerevisiae, showed extensive blocks of homology, with non-homologous sequences between these blocks being generally much longer in Neurospora than in yeast. Computer-predicted protein secondary structure of pyr-4 and URA3 was conserved within equivalent blocks. Upstream sequences of pyr-4 were compared with other sequenced Neurospora genes and possible promoter sequences identified.
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D002262:Carboxy-Lyases / Q000235:genetics*; D003001:Cloning, Molecular; D004251:DNA Transposable Elements; D004926:Escherichia coli / Q000235:genetics; D005796:Genes; D005800:Genes, Fungal; D009491:Neurospora / Q000235:genetics*; D009492:Neurospora crassa / Q000201:enzymology / Q000235:genetics*; D009964:Orotidine-5'-Phosphate Decarboxylase / Q000235:genetics*; D010957:Plasmids
chemical_list: D004251:DNA Transposable Elements; D002262:Carboxy-Lyases; D009964:Orotidine-5'-Phosphate Decarboxylase