1klo

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spinqualitylabelsall models 1klo, resolution 2.1Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

CRYSTAL STRUCTURE OF THREE CONSECUTIVE LAMININ-TYPE EPIDERMAL GROWTH FACTOR-LIKE (LE) MODULES OF LAMININ GAMMA1 CHAIN HARBORING THE NIDOGEN BINDING SITE

Overview

The structure of three consecutive laminin-type EGF-like (LE) modules of, mouse laminin gammma1 chain, gamma1III3-5 (positions 738 to 899), has been, determined by multiple isomorphous replacement in a crystal of space group, p6(4)22 (a=b=74.57 angstroms, c = 185.11 angstroms and gamma = 120, degrees). The crystal structure was refined using restrained, crystallographic refinement to an R-factor of 19.72% for 14,983, independent reflections with intensities F(obs)> 0 at 2.1 angstroms, resolution, with root mean square deviation of 0.012 angstroms and 1.690, degrees from ideal bond lengths and bond angles, respectively. The final, model consisted of 1179 (non-hydrogen) protein atoms within 162 residues, and 119 water molecules. The molecule showed a rod-like structure of about, 76 angstroms length with individual modules twisted relative to each other, by about 70 degrees. Each module has the same disulfide bond connections, Cys1-Cys3 (loop a), Cys2-Cys4 (loop b), Cys5-Cys6 (loop c) and Cys7-Cys8, (loop d), the first three being identical to epidermal growth factor, (EGF). All three LE modules showed little secondary structure which was, mainly restricted to loop d, but they differed in several other details of, their structure. The interface contacts between the LE modules are based, on hydrogen bonds and hydrophobic interactions between the hydrophobic, core of loop d of the preceding module and the first cysteine and an, exposed residue in loop b of the following module. Module 4 was previously, shown to contribute the major nidogen binding site of laminis and, site-directed mutagenesis demonstrated a specific binding role for Asp800, Asn802, Val804 and Tyr819 in loops a and c. The side-chain of these four, residues are all located on the surface in a linear array and separated by, a distance of 17 angstroms between Tyr819 and Val804. The entire nidogen, binding site is stabilized via main-chain hydrogen bonds which are in part, derived from the link between loops b and c (residues Leu815 and Lys816)., The data demonstrate the unique nature of the LE modules and only a remote, similarity to EGF. They also indicate that the crucial residues in the, binding loops provide direct contacts with nidogen and explain the, synergism between loops a and c which is essential for binding.

About this Structure

1KLO is a Single protein structure of sequence from Mus musculus. Full crystallographic information is available from OCA.

Reference

Crystal structure of three consecutive laminin-type epidermal growth factor-like (LE) modules of laminin gamma1 chain harboring the nidogen binding site., Stetefeld J, Mayer U, Timpl R, Huber R, J Mol Biol. 1996 Apr 5;257(3):644-57. PMID:8648630

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