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1gcm
From Proteopedia
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GCN4 LEUCINE ZIPPER CORE MUTANT P-LI
Overview
Subunit oligomerization in many proteins is mediated by short coiled-coil, motifs. These motifs share a characteristic seven-amino-acid repeat, containing hydrophobic residues at the first (a) and fourth (d) positions., Despite this common pattern, different sequences form two-, three- and, four-stranded helical ropes. We have investigated the basis for oligomer, choice by characterizing variants of the GCN4 leucine-zipper dimerization, domain that adopt trimeric or tetrameric structures in response to, mutations at the a and d positions. We now report the high-resolution, X-ray crystal structure of an isoleucine-containing mutant that folds into, a parallel three-stranded, alpha-helical coiled coil. In contrast to the, dimer and tetramer structures, the interior packing of the trimer can, accommodate beta-branched residues in the most preferred rotamer at both, hydrophobic positions. Compatibility of the shape of the core amino acids, with the distinct packing spaces in the two-, three- and four-stranded, conformations appears to determine the oligomerization state of the GCN4, leucine-zipper variants.
About this Structure
1GCM is a Single protein structure of sequence from Saccharomyces cerevisiae with ACE as ligand. Full crystallographic information is available from OCA.
Reference
Crystal structure of an isoleucine-zipper trimer., Harbury PB, Kim PS, Alber T, Nature. 1994 Sep 1;371(6492):80-3. PMID:8072533
Page seeded by OCA on Tue Nov 20 15:56:44 2007
