Porcine factor V: cDNA cloning, gene mapping, three-dimensional protein modeling of membrane binding sites and comparative anatomy of domains

Factor V is a plasma protein essential for blood coagulation. This protein is involved in activated protein C resistance, the most common inherited th rombotic disorder known. We utilized the polymerase chain reaction to clone the porcine factor V gene by generating overlapping clones amplified with primers chosen by comparison with known nucleotide sequences. The porcine f actor V cDNA contig encodes a predicted 2258-amino acid protein, making it the largest in comparison to the bovine, human, and murine proteins. Porcin e factor V has the highest level of homology with bovine factor V, but also has high levels of conservation of important residues with all the species . Radiation hybrid mapping assigned the porcine factor V gene to chromosome 4. Three-dimensional models of factor V were generated and used to analyze membrane-binding sites in terms of conserved, and therefore likely importa nt residues.