title: Coexpression of two closely linked avian genes for purine nucleotide synthesis from a bidirectional promoter.
abstract: Two avian genes encoding essential steps in the purine nucleotide biosynthetic pathway are transcribed divergently from a bidirectional promoter element. The bidirectional promoter, embedded in a CpG island, directs coexpression of GPAT and AIRC genes from distinct transcriptional start sites 229 bp apart. The bidirectional promoter can be divided in half, with each half retaining partial activity towards the cognate gene. GPAT and AIRC genes encode the enzymes that catalyze step 1 and steps 6 plus 7, respectively, in the de novo purine biosynthetic pathway. This is the first report of genes coding for structurally unrelated enzymes of the same pathway that are tightly linked and transcribed divergently from a bidirectional promoter. This arrangement has the potential to provide for regulated coexpression comparable to that in a prokaryotic operon.
authors.affiliation: Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907-1153.
authors.forename: A
authors.initials: A
authors.lastname: Gavalas
authors.forename: J E
authors.initials: JE
authors.lastname: Dixon
authors.forename: K A
authors.initials: KA
authors.lastname: Brayton
authors.forename: H
authors.initials: H
authors.lastname: Zalkin
mesh_terms: D000582:Amidophosphoribosyltransferase / Q000235:genetics*; D000818:Animals; D001483:Base Sequence; D019731:Carbon-Nitrogen Ligases; D002645:Chickens / Q000235:genetics*; D015971:Gene Expression Regulation, Enzymologic; D005796:Genes; D008040:Genetic Linkage; D008025:Ligases / Q000235:genetics*; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011685:Purine Nucleotides / Q000737:chemistry*; D012333:RNA, Messenger / Q000235:genetics; D015183:Restriction Mapping; D014158:Transcription, Genetic
chemical_list: D011685:Purine Nucleotides; D012333:RNA, Messenger; D000582:Amidophosphoribosyltransferase; D008025:Ligases; D019731:Carbon-Nitrogen Ligases; C022380:phosphoribosylaminoimidazole synthase