Crystal structure of the second fibronectin type III (FN3) domain from human collagen α 1 type XX

Collagen α 1 type XX, which contains fibronectin type III (FN3) repeats involving six FN3 domains (referred to as the FN#1 – FN#6 domains), is an unusual member of the fibril-associated collagens with interrupted triple helices (FACIT) subfamily of collagens. The results of standard protein BLAST suggest that the FN3 repeats might contribute to collagen α 1 type XX acting as a cytokine receptor. To date, solution NMR structures of the FN#3, FN#4 and FN#6 domains have been determined. To obtain further structural evidence to understand the relationship between the structure and function of the FN3 repeats from collagen α 1 type XX, the crystal structure of the FN#2 domain from human collagen α 1 type XX (residues Pro386 – Pro466; referred to as FN2-HCXX) was solved at 2.5   Å resolution. The crystal structure of FN2-HCXX shows an immunoglobulin-like fold containing a β -sandwich structure, which is formed by a three-stranded β -sheet ( β 1, β 2 and β 5) packed onto a four-stranded β -sheet ( β 3, β 4, β 6 and β 7). Two consensus domains, tencon and fibcon, are structural analogues of FN2-HCXX. Fn8, an FN3 domain from human oncofoetal fibronectin, is the closest structural analogue of FN2-HCXX derived from a naturally occurring sequence. Based solely on the structural similarity of FN2-HCXX to other FN3 domains, the detailed functions of FN2-HCXX and the FN3 repeats in collagen α 1 type XX cannot be identified.

Source: Acta Crystallographica Section F - November 21, 2017 Category: Biochemistry Authors: Zhao, J. Ren, J. Wang, N. Cheng, Z. Yang, R. Lin, G. Guo, Y. Cai, D. Xie, Y. Zhao, X. Tags: crystal structure fibronectin type III domain FN3 domain collagen α 1 type XX research communications Source Type: research