InterPro : IPR001442

Name  Collagen IV, non-collagenous Short Name  Collagen_VI_NC
Type  Repeat Description  Collagens are major components of the extracellular matrices of all metazoan life and play crucial roles in developmental processes and tissue homeostasis. Collagens are composed of three polypeptide chains (alpha chains) that fold together to form the characteristic triple helical collagenous domain. Some types of triple helical protomers contain genetically identical alpha chains forming homotrimers, whereas others contain two or three different alpha chains forming heterotrimers. The sequences required to form a collagenous domain are Gly-X-Y repeats in which the X and Y positions are frequently proline and hydroxyproline. Glycine is required every third residue as it is the only amino acid small enough to pack into the central core of the triple helix. The triple helix-forming parts are surrounded by non-collagenous (NC) domains of variable sequence, size, and shape. Even if the triple helical parts represent the most striking feature of collagens, tissue specificity as well as defined binding of non-collagens seem to be encoded in the NC domains. The terminal NC domains are excised, modified, or incorporated directly into the final suprastructure, depending on protomer type and function [, ]. Type IV collagen is one of the major constituents of basement membranes, a specialised form of extracellular matrix underlying epithelia that compartmentalises tissues and provides molecular signals for influencing cell behaviour. Each type IV chain contains a long triple-helical collagenous domain flanked by a short 7S domain of 25 residues and a globular non-collagenous NC1 domain of ~230 residues at the N and C terminus, respectively. In protomer assembly, the NC1 domains (monomers) of three chains interact, forming an NC1 trimer, to select and register chains for triple helix formation. In network assembly, the NC1 trimers of two protomers interact, forming a NC1 hexamer structure, to select and connect protomers [, , ]. The collagen IV NC1 domain contains 12 cysteines, and all of them are involved in disulphide bonds. It folds into a tertiary structure with predominantly beta-strands. The collagen IV NC1 domain is composed of two similarly folded subdomains stabilised by 3 intrachain dissulphide bonds involving the following pairs: C1-C6, C2-C5, and C3-C4. Each subdomain represents a compact disulphide-stabilised triangular structure, from which a finger-like hairpin loop projects into an incompletely formed six-stranded beta-sheet of an adjacent subdomain of the same or of an adjacent chain clamping the subdomains tightly together [, , ]. This duplicated domain is present at the C-terminal of type 4 collagen, the major structural component of glomerular basement membranes (GMB) forming a 'chicken-wire' meshwork together with laminins, proteoglycans and entactin/nidogen. Mutations in alpha-5 collagen IV are associated withX-linked Alport syndrome.
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InterPro protein domain ID --> Contigs


GO Displayer



0 Child Features

0 Contains

1 Found In

Id Name Short Name Type
IPR016187 C-type lectin fold C-type_lectin_fold Domain

0 Parent Features

5 Publications

First Author Title Year Journal Volume Pages
Bork P The modular architecture of vertebrate collagens. 1992 FEBS Lett 307 49-54
Than ME The 1.9-A crystal structure of the noncollagenous (NC1) domain of human placenta collagen IV shows stabilization via a novel type of covalent Met-Lys cross-link. 2002 Proc Natl Acad Sci U S A 99 6607-12
Sundaramoorthy M Crystal structure of NC1 domains. Structural basis for type IV collagen assembly in basement membranes. 2002 J Biol Chem 277 31142-53
Vanacore RM 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. 2004 J Biol Chem 279 44723-30
Boot-Handford RP Fibrillar collagen: the key to vertebrate evolution? A tale of molecular incest. 2003 Bioessays 25 142-51

To cite PlanMine, please refer to the following publication:

Brandl, H., Moon, H., Vila-Farré, M., Liu, S.-Y., Henry, I., & Rink, J. C.
PlanMine - a mineable resource of planarian biology and biodiversity.
Nucleic Acids Research, gkv1148. doi:10.1093/nar/gkv1148 (2015)