1T61

crystal structure of collagen IV NC1 domain from placenta basement membrane

Summary for 1T61

• Entry DOI: 10.2210/pdb1t61/pdb
• Related: 1LI1 1M3D 1T60
• Descriptor: Type IV Collagen, POTASSIUM ION, CHLORIDE ION, ... (7 entities in total)
• Functional Keywords: basement membrane, type iv collagen, nc1 domain, structural protein
• Biological source: Bos taurus (cattle); More
• Cellular location: Secreted, extracellular space, extracellular matrix, basement membrane: Q7SIB3
• Total number of polymer chains: 6
• Total formula weight: 152938.77

Authors

Vanacore, R.M.,Shanmugasundararaj, S.,Friedman, D.B.,Bondar, O.,Hudson, B.G.,Sundaramoorthy, M. (deposition date: 2004-05-05, release date: 2004-09-21, Last modification date: 2024-10-30)

Primary citation

Vanacore, R.M.,Shanmugasundararaj, S.,Friedman, D.B.,Bondar, O.,Hudson, B.G.,Sundaramoorthy, M.
The alpha1.alpha2 network of collagen IV. Reinforced stabilization of the noncollagenous domain-1 by noncovalent forces and the absence of Met-Lys cross-links
J.Biol.Chem., 279:44723-44730, 2004

PubMed Abstract: Collagen IV networks are present in all metazoa and underlie epithelia as a component of basement membranes. The networks are essential for tissue function and are defective in disease. They are assembled by the oligomerization of triple-helical protomers that are linked end-to-end. At the C terminus, two protomers are linked head-to-head by interactions of their trimeric noncollagenous domains, forming a hexamer structure. This linkage in the alpha1.alpha2 network is stabilized by a putative covalent Met-Lys cross-link between the trimer-trimer interface (Than, M. E., Henrich, S., Huber, R., Ries, A., Mann, K., Kuhn, K., Timpl, R., Bourenkov, G. P., Bartunik, H. D., and Bode, W. (2002) Proc. Natl. Acad. Sci. U. S. A. 99, 6607-6612) forming a nonreducible dimer that connects the hexamer. In the present study, this cross-link was further investigated by: (a) comparing the 1.5-A resolution crystal structures of the alpha1.alpha2 hexamers from bovine placenta and lens capsule basement membranes, (b) mass spectrometric analysis of monomer and nonreducible dimer subunits of placenta basement membrane hexamers, and (c) hexamer dissociation/re-association studies. The findings rule out the novel Met-Lys cross-link, as well as other covalent cross-links, but establish that the nonreducible dimer is an inherent structural feature of a subpopulation of hexamers. The dimers reflect the reinforced stabilization, by noncovalent forces, of the connection between two adjoining protomers of a network. The reinforcement extends to other types of collagen IV networks, and it underlies the cryptic nature of a B-cell epitope of the alpha3.alpha4.alpha5 hexamer, implicating the stabilization event in the etiology and pathogenesis of Goodpasture autoimmune disease.

PubMed: 15299013
DOI: 10.1074/jbc.M406344200

Experimental method

X-RAY DIFFRACTION (1.5 Å)