1tmr | pdb_00001tmr
THE STRUCTURE OF A 19 RESIDUE FRAGMENT FROM THE C-LOOP OF THE FOURTH EPIDERMAL GROWTH FACTOR-LIKE DOMAIN OF THROMBOMODULIN
Structural highlights
Disease[TRBM_HUMAN] Defects in THBD are the cause of thrombophilia due to thrombomodulin defect (THPH12) [MIM:614486]. A hemostatic disorder characterized by a tendency to thrombosis.[1] [2] [3] Defects in THBD are a cause of susceptibility to hemolytic uremic syndrome atypical type 6 (AHUS6) [MIM:612926]. An atypical form of hemolytic uremic syndrome. It is a complex genetic disease characterized by microangiopathic hemolytic anemia, thrombocytopenia, renal failure and absence of episodes of enterocolitis and diarrhea. In contrast to typical hemolytic uremic syndrome, atypical forms have a poorer prognosis, with higher death rates and frequent progression to end-stage renal disease. Note=Susceptibility to the development of atypical hemolytic uremic syndrome can be conferred by mutations in various components of or regulatory factors in the complement cascade system. Other genes may play a role in modifying the phenotype.[4] [5] Function[TRBM_HUMAN] Thrombomodulin is a specific endothelial cell receptor that forms a 1:1 stoichiometric complex with thrombin. This complex is responsible for the conversion of protein C to the activated protein C (protein Ca). Once evolved, protein Ca scissions the activated cofactors of the coagulation mechanism, factor Va and factor VIIIa, and thereby reduces the amount of thrombin generated. Publication Abstract from PubMedThe solution structure has been determined for a 19-residue peptide that is fully folded at room temperature. The sequence of this peptide is based on the C-loop, residues 371-389, of the fourth epidermal growth factor-like domain of thrombomodulin, a protein that acts as a cofactor for the thrombin activation of protein C. Despite its small size, the peptide forms a compact structure with almost no repeating secondary structure. The results indicate the structure is held together by hydrophobic interactions, which in turn stabilize the two beta-turns in the structure. The first beta-turn in the C-loop represents a conserved motif that is found in the published structures of five other epidermal growth factor-like proteins. The critical role of Phe376 in the stabilization of the first beta-turn is consistent with mutagenesis data with soluble thrombomodulin. The results also show that a small subdomain of a larger protein can fold independently, and therefore it could act as an initiation site for further folding. The structure of a 19-residue fragment from the C-loop of the fourth epidermal growth factor-like domain of thrombomodulin.,Adler M, Seto MH, Nitecki DE, Lin JH, Light DR, Morser J J Biol Chem. 1995 Oct 6;270(40):23366-72. PMID:7559494[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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