4AQT

Laminin gamma1 LN-LE1-2 structure

Summary for 4AQT

• Entry DOI: 10.2210/pdb4aqt/pdb
• Related: 1KLO 1NPE 1TLE 4AQS
• Descriptor: LAMININ SUBUNIT GAMMA-1, beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, CALCIUM ION, ... (4 entities in total)
• Functional Keywords: cell adhesion
• Biological source: MUS MUSCULUS (HOUSE MOUSE)
• Cellular location: Secreted, extracellular space, extracellular matrix, basement membrane: P02468
• Total number of polymer chains: 1
• Total formula weight: 42824.23

Authors

Carafoli, F.,Hussain, S.,Hohenester, E. (deposition date: 2012-04-19, release date: 2012-08-15, Last modification date: 2024-11-20)

Primary citation

Carafoli, F.,Hussain, S.,Hohenester, E.
Crystal Structures of the Network-Forming Short-Arm Tips of the Laminin Beta1 and Gamma1 Chains.
Plos One, 7:42473-, 2012

PubMed Abstract: The heterotrimeric laminins are a defining component of basement membranes and essential for tissue formation and function in all animals. The three short arms of the cross-shaped laminin molecule are composed of one chain each and their tips mediate the formation of a polymeric network. The structural basis for laminin polymerisation is unknown. We have determined crystal structures of the short-arm tips of the mouse laminin β1 and γ1 chains, which are grossly similar to the previously determined structure of the corresponding α5 chain region. The short-arm tips consist of a laminin N-terminal (LN) domain that is attached like the head of a flower to a rod-like stem formed by tandem laminin-type epidermal growth factor-like (LE) domains. The LN domain is a β-sandwich with elaborate loop regions that differ between chains. The γ1 LN domain uniquely contains a calcium binding site. The LE domains have little regular structure and are stabilised by cysteines that are disulphide-linked 1-3, 2-4, 5-6 and 7-8 in all chains. The LN surface is not conserved across the α, β and γ chains, but within each chain subfamily there is a striking concentration of conserved residues on one face of the β-sandwich, while the opposite face invariably is shielded by glycans. We propose that the extensive conserved patches on the β and γ LN domains mediate the binding of these two chains to each other, and that the α chain LN domain subsequently binds to the composite β-γ surface. Mutations in the laminin β2 LN domain causing Pierson syndrome are likely to impair the folding of the β2 chain or its ability to form network interactions.

PubMed: 22860131
DOI: 10.1371/JOURNAL.PONE.0042473

Experimental method

X-RAY DIFFRACTION (3.2 Å)