title: Isolation and characterization of human blood-coagulation factor X cDNA.
abstract: Using synthetic oligodeoxynucleotides as probes, we have isolated factor X cDNA from human liver cDNA library. We sequenced the 1430-bp cDNA which spans the coding region of the mature factor X and contains the polyadenylation signal and poly(A) tail. The amino acid (aa) sequence is in agreement with the published aa sequence. The nucleotide (nt) sequence of cDNA confirmed that factor X is synthesized and secreted as a single-chain precursor, and then converted into dimeric form by proteolytic cleavage of an internal tripeptide. From the nt sequence, it was also predicted that like other secretory proteins, human factor X is synthesized with a leader sequence (prepro-protein). The 5'-coding region of factor X cDNA is 60 and 40% homologous to the corresponding regions of factor IX and prothrombin genes, respectively. This supports the hypothesis of gene evolution by gene duplication followed by divergence.
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000302:isolation & purification*; D004262:DNA Restriction Enzymes; D005170:Factor X / Q000235:genetics*; D005796:Genes; D006801:Humans; D008099:Liver / Q000201:enzymology
chemical_list: D005170:Factor X; D004247:DNA; D004262:DNA Restriction Enzymes