The invention provides novel polynucleotides and polypeptides encoded by such polynucleotides and mutants or variants thereof that correspond to a novel human prothrombinase-like polypeptide. These polynucleotides comprise nucleic acid sequences isolated from cDNA library from human ovary (Hyseq clone identification number 7735656). Other aspects of the invention include vectors containing processes for producing novel human prothrombinase-like polypeptides, and antibodies specific for such polypeptides.