[COIA1_HUMAN] Defects in COL18A1 are a cause of Knobloch syndrome type 1 (KNO1) [MIM:267750]. An autosomal recessive disorder defined by the occurrence of high myopia, vitreoretinal degeneration with retinal detachment, macular abnormalities and occipital encephalocele.
[COIA1_HUMAN] COLA18A probably plays a major role in determining the retinal structure as well as in the closure of the neural tube. Endostatin potently inhibits endothelial cell proliferation and angiogenesis. May inhibit angiogenesis by binding to the heparan sulfate proteoglycans involved in growth factor signaling.
Collagens contain a unique triple-helical structure with a repeating sequence -G-X-Y-, where proline and hydroxyproline are major constituents in X and Y positions, respectively. Folding of the collagen triple helix requires trimerization domains. Once trimerized, collagen chains are correctly aligned and the folding of the triple helix proceeds in a zipper-like fashion. Here we report the isolation, characterization, and crystal structure of the trimerization domain of human type XVIII collagen, a member of the multiplexin family. This domain differs from all other known trimerization domains in other collagens and exhibits a high trimerization potential at picomolar concentrations. Strong chain association and high specificity of binding are needed for multiplexins, which are present at very low levels.
Crystal structure of human collagen XVIII trimerization domain: A novel collagen trimerization Fold.,Boudko SP, Sasaki T, Engel J, Lerch TF, Nix J, Chapman MS, Bachinger HP J Mol Biol. 2009 Sep 25;392(3):787-802. Epub 2009 Jul 23. PMID:19631658
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
↑ Sertie AL, Sossi V, Camargo AA, Zatz M, Brahe C, Passos-Bueno MR. Collagen XVIII, containing an endogenous inhibitor of angiogenesis and tumor growth, plays a critical role in the maintenance of retinal structure and in neural tube closure (Knobloch syndrome). Hum Mol Genet. 2000 Aug 12;9(13):2051-8. PMID:10942434
↑ Boudko SP, Sasaki T, Engel J, Lerch TF, Nix J, Chapman MS, Bachinger HP. Crystal structure of human collagen XVIII trimerization domain: A novel collagen trimerization Fold. J Mol Biol. 2009 Sep 25;392(3):787-802. Epub 2009 Jul 23. PMID:19631658 doi:10.1016/j.jmb.2009.07.057