The 1.9-Å crystal structure of the noncollagenous (NC1) domain of human placenta collagen IV shows stabilization via a novel type of covalent Met-Lys cross-link
The 1.9-Å crystal structure of the noncollagenous (NC1) domain of human placenta collagen IV shows stabilization via a novel type of covalent Met-Lys cross-link
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DOI：
10.1073/pnas.062183499
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发表时间：
2002-05-14
影响因子：
11.1
通讯作者：
Bode, W
中科院分区：
文献类型：
--
作者：
Than, ME;Henrich, S;Bode, W
Triple-helical collagen IV protomers associate through their N- and C-termini forming a three-dimensional network, which provides basement membranes with an anchoring scaffold and mechanical strength. The noncollagenous (NC1) domain of the C-terminal junction between two adjacent collagen IV protomers from human placenta was crystallized and its 1.9-Angstrom structure was solved by multiple anomalous diffraction (MAD) phasing, This hexameric NC1 particle is composed of two trimeric caps, which interact through a large planar interface. Each cap is formed by two alpha1 fragments and one alpha2 fragment with a similar previously uncharacterized fold, segmentally arranged around an axial tunnel. Each monomer chain folds into two structurally very similar subdomains, which each contain a finger-like hairpin loop that inserts into a six-stranded beta-sheet of the neighboring subdomain of the same or the adjacent chain. Thus each trimer forms a quite regular, but non-classical, sixfold propeller. The trimer-trimer interaction is further stabilized by a previously uncharacterized type of covalent cross-link between the side chains of a Met and a Lys residue of the alpha1 and alpha2 chains from opposite trimers, explaining previous findings of nonreducible cross-links in NC1. This structure provides insights into NC1-related diseases such as Goodpasture and Alport syndromes.
