Vitamin K-dependent blood coagulation proteins form hetero-dimers.
The later stages of the blood coagulation cascade are characterized by the presence of vitamin K-dependent proteins and their involvement in membrane-bound, multi-protein converting complexes with an essential requirement for calcium ions. Specific interactions between zymogens and activating enzymes have not yet been identified. Here we describe a crystallographic study of prothrombin fragment 1 (residues 1-156 of prothrombin) which indicates that vitamin K-dependent coagulation proteins have specific association sites that allow them to form hetero-dimers. The calcium-induced formation of a hetero-dimer between fragment 1 and factor X is demonstrated by cross-linking. Such hetero-dimers of vitamin K-dependent proteins could be significant in the coagulation system.
Harlos
K
K
Laboratory of Molecular Biophysics, University of Oxford, UK.
Holland
S K
SK
Boys
C W
CW
Burgess
A I
AI
Esnouf
M P
MP
Blake
C C
CC
D001777:Blood Coagulation; D001779:Blood Coagulation Factors / Q000502:physiology*; D005342:Fibrinolysis; D006801:Humans; D046911:Macromolecular Substances; D008958:Models, Molecular; D011487:Protein Conformation; D011516:Prothrombin / Q000502:physiology*; D013917:Thrombin / Q000502:physiology; D014812:Vitamin K / Q000502:physiology*
D001779:Blood Coagulation Factors; D046911:Macromolecular Substances; D014812:Vitamin K; D011516:Prothrombin; D013917:Thrombin