Characterization of the complementary deoxyribonucleic acid and gene coding for human prothrombin.

Area of Science:

• Molecular Biology
• Genetics
• Biochemistry

Background:

• Human prothrombin is a crucial protein in the blood coagulation cascade.
• Understanding its gene structure and cDNA is vital for studying prothrombin-related disorders.

Purpose of the Study:

• To determine the DNA sequences of human prothrombin's cDNA and a portion of its gene.
• To analyze the genetic elements and coding regions of human prothrombin.

Main Methods:

• Complementary DNA (cDNA) sequencing of human prothrombin.
• Screening a human fetal liver genomic DNA library using prothrombin cDNA as a probe.
• Restriction endonuclease mapping and sequencing of genomic DNA inserts.

Main Results:

• The human prothrombin cDNA sequence (2005 bp) was determined, including leader sequence, mature protein, stop codon, and poly(A) tail.
• A genomic DNA fragment containing approximately half of the human prothrombin gene was isolated and characterized.
• This genomic DNA contained six introns and five exons (coding for residues 144-448), with repetitive DNA in introns.

Conclusions:

• The cDNA sequence provides insights into the synthesis and processing of circulating prothrombin.
• The characterized gene portion reveals the exon-intron structure of the human prothrombin gene.
• The presence of repetitive DNA elements in introns suggests potential regulatory roles or evolutionary significance.