title: Blood coagulation factor X mRNA encodes a single polypeptide chain containing a prepro leader sequence.
abstract: Thirty thousand colonies of a bovine liver cDNA library were screened with a mixture of synthetic oligodeoxyribonucleotides coding for bovine factor X. Five positive colonies were identified, and plasmid DNA was isolated. Cleavage with restriction endonucleases showed that these plasmids (designated pBX1 -5) contained inserts of 1530bp , 770bp , 700bp , 1100bp and 930bp . DNA sequence analysis of the plasmid with the largest insert ( pBX1 ) confirmed that bovine factor X cDNAs had been cloned. The cDNA sequence predicts that factor X is synthesized as a single chain precursor in which the light and heavy chains of plasma factor X are linked by the dipeptide Arg-Arg. The cDNA sequence also predicts that factor X is synthesized with a prepro leader peptide. We propose that at least five specific proteolytic events occur during the conversion of prepro -factor X to plasma factor Xa.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002417:Cattle; D003001:Cloning, Molecular; D004247:DNA / Q000032:analysis; D004262:DNA Restriction Enzymes; D005164:Factor IX / Q000235:genetics; D005170:Factor X / Q000235:genetics*; D005796:Genes; D006801:Humans; D009838:Oligodeoxyribonucleotides / Q000235:genetics; D011498:Protein Precursors / Q000235:genetics*; D011516:Prothrombin / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics*
chemical_list: D009838:Oligodeoxyribonucleotides; D011498:Protein Precursors; D012333:RNA, Messenger; D011516:Prothrombin; D005164:Factor IX; D005170:Factor X; D004247:DNA; D004262:DNA Restriction Enzymes