THE 1.2 ANGSTROM STRUCTURE OF KUNITZ TYPE DOMAIN C5
[CO6A3_HUMAN] Defects in COL6A3 are a cause of Bethlem myopathy (BM) [MIM:158810]. BM is a rare autosomal dominant proximal myopathy characterized by early childhood onset (complete penetrance by the age of 5) and joint contractures most frequently affecting the elbows and ankles.     Defects in COL6A3 are a cause of Ullrich congenital muscular dystrophy (UCMD) [MIM:254090]; also known as Ullrich scleroatonic muscular dystrophy. UCMD is an autosomal recessive congenital myopathy characterized by muscle weakness and multiple joint contractures, generally noted at birth or early infancy. The clinical course is more severe than in Bethlem myopathy. 
[CO6A3_HUMAN] Collagen VI acts as a cell-binding protein.
Publication Abstract from PubMed
The recombinant Kunitz-type domain (C5) of human collagen alpha3(VI) chain was previously described at 1.6 A resolution at room temperature. By changing the crystallization conditions and using synchrotron radiation, we are able to record diffraction data to 1.2 A resolution for crystals of the same space group at 291 K. The protein-water-ion model has been refined anisotropically against these new data using the program SHELXL93; the results converged to an R factor of 15.0%, with all data between 7 and 1.2 A. The final electron-density map reveals a clear chain tracing with a few disordered residues and five residues out of 58 that present alternate conformations. The Cys14-Cys38 bond presents the less frequently observed left-hand conformation (chi1 = -60 degrees). The solvent molecules and a phosphate ion are well ordered with an average B of 38 A2. The high-resolution structure reveals the N and C termini which were missing from the 1.6 A structure.
1.2 A refinement of the Kunitz-type domain from the alpha3 chain of human type VI collagen.,Merigeau K, Arnoux B, Perahia D, Norris K, Norris F, Ducruix A Acta Crystallogr D Biol Crystallogr. 1998 May 1;54(Pt 3):306-12. PMID:9761897
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.