PMID: 28988748
Authors:
Garcia-Castellanos R, Nielsen NS, Runager K, Thogersen IB, Lukassen MV, Poulsen ET, Goulas T, Enghild JJ, Gomis-Ruth FX
Title:
Structural and Functional Implications of Human Transforming Growth Factor beta-Induced Protein, TGFBIp, in Corneal Dystrophies.
Journal:
Structure. 2017 Sep 27. pii: S0969-2126(17)30292-7. doi:, 10.1016/j.str.2017.09.001.
Abstract:
A major cause of visual impairment, corneal dystrophies result from accumulation of protein deposits in the cornea. One of the proteins involved is transforming growth factor beta-induced protein (TGFBIp), an extracellular matrix component that interacts with integrins but also produces corneal deposits when mutated. Human TGFBIp is a multi-domain 683-residue protein, which contains one CROPT domain and four FAS1 domains. Its structure spans approximately 120 A and reveals that vicinal domains FAS1-1/FAS1-2 and FAS1-3/FAS1-4 tightly interact in an equivalent manner. The FAS1 domains are sandwiches of two orthogonal four-stranded beta sheets decorated with two three-helix insertions. The N-terminal FAS1 dimer forms a compact moiety with the structurally novel CROPT domain, which is a five-stranded all-beta cysteine-knot solely found in TGFBIp and periostin. The overall TGFBIp architecture discloses regions for integrin binding and that most dystrophic mutations cluster at both molecule ends, within domains FAS1-1 and FAS1-4.