title: Cloning and analysis of a cDNA coding for bovine prothrombin.
abstract: Poly(A)-RNA enriched for prothrombin was isolated by specific immunoprecipitation of bovine liver polysomes. Prothrombin consisted of about 8% of the cell-free translation products of this RNA. A double-stranded cDNA was synthesized by using reverse transcriptase (RNA-dependent DNA nucleotidyltransferase) and made blunt-ended with nuclease S1. After tailing with dCTP and terminal transferase, the double-stranded cDNA was annealed to pBR322 DNA that had been cleaved previously at the single Pst I site and similarly tailed with dGTP. The resulting plasmids were used to transform Escherichia coli strain RR1 under P3-EK1 conditions. Sixty-three tetracycline-resistant clones were obtained that hybridized to 32P-labeled cDNA synthesized from prothrombin-enriched mRNA. Recombinants containing cDNA to prothrombin mRNA sequences were screened by a solution hybridization assay with a [3H]cDNA synthesized from mRNA. This enriched mRNA was 50% prothrombin mRNA, as determined by a reticulocyte lysate translation assay. Three positive clones were identified by this assay; they contained bovine DNA inserts of 700, 500, and 400 base pairs. The DNA sequence of the 700-base-pair insert was then determined. This recombinant plasmid contained DNA coding for the carboxyl-terminal 160 residues of bovine prothrombin followed by a noncoding region of 119 base pairs and a poly(A) tail of 60 base pairs.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002417:Cattle; D003001:Cloning, Molecular; D004262:DNA Restriction Enzymes; D004926:Escherichia coli / Q000235:genetics; D005796:Genes; D005813:Genes, Synthetic; D005822:Genetic Vectors; D010957:Plasmids; D011516:Prothrombin / Q000235:genetics*
chemical_list: D011516:Prothrombin; D004262:DNA Restriction Enzymes