Mutational mapping of functional residues in tissue factor: identification of factor VII recognition determinants in both structural modules of the predicted cytokine receptor homology domain

A study of residue side chains reveals that the tissue factor extracellular domain possibly adopts the cytokine receptor homology unit folding pattern with two seven-beta-strand modules. Mutational analysis suggests that important residues are spatially closer and present as a cluster on the beta-strand module boundary. Residues involved in ligand binding occur in positions corresponding to ligand interactive residues.