1len

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spinqualitylabelsall models 1len, resolution 1.8Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

REFINEMENT OF TWO CRYSTAL FORMS OF LENTIL LECTIN AT 1.8 ANGSTROMS RESOLUTION

Overview

The structures of two crystal forms of lentil lectin are determined and, refined at high resolution. Orthorhombic lentil lectin is refined at 1.80, A resolution to an R-factor of 0.184 and monoclinic lentil lectin at 1.75, A resolution to an R-factor of 0.175. These two structures are compared to, each other and to the other available legume lectin structures. The, monosaccharide binding pocket of each lectin monomer contains a tightly, bound phosphate ion. This phosphate makes hydrogen bonding contacts with, Asp-81 beta, Gly-99 beta, and Asn-125 beta, three residues that are highly, conserved in most of the known legume lectin sequences and essential for, monosaccharide recognition in all legume lectin crystal structures, described thus far. A detailed analysis of the composition and properties, of the hydrophobic contact network and hydrophobic nuclei in lentil lectin, is presented. Contact map calculations reveal that dense clusters of, nonpolar as well as polar side chains play a major role in secondary, structure packing. This is illustrated by a large cluster of 24 mainly, hydrophobic amino acids that is responsible for the majority of packing, interactions between the two beta-sheets. Another series of four smaller, and less hydrophobic clusters is found to mediate the packing of a number, of loop structures upon the front sheet. A very dense, but not very, conserved cluster is found to stabilize the transition metal binding site., The highly conserved and invariant nonpolar residues are distributed, asymmetrically over the protein.

About this Structure

1LEN is a Protein complex structure of sequences from Lens culinaris with PO4, MN and CA as ligands. Full crystallographic information is available from OCA.

Reference

Structural analysis of two crystal forms of lentil lectin at 1.8 A resolution., Loris R, Van Overberge D, Dao-Thi MH, Poortmans F, Maene N, Wyns L, Proteins. 1994 Dec;20(4):330-46. PMID:7731952

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