title: Active site of bovine factor XI (plasma thromboplastin antecedent).
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D010450:Endopeptidases / Q000097:blood; D005172:Factor XI / Q000378:metabolism; D012694:Serine
chemical_list: D012694:Serine; D005172:Factor XI; D010450:Endopeptidases