1ejp
From Proteopedia
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SOLUTION STRUCTURE OF THE SYNDECAN-4 WHOLE CYTOPLASMIC DOMAIN
Overview
The syndecans, transmembrane proteoglycans which are involved in the, organization of cytoskeleton and/or actin microfilaments, have important, roles as cell surface receptors during cell-cell and/or cell-matrix, interactions. Since previous studies indicate that the function of the, syndecan-4 cytoplasmic domain is dependent on its oligomeric status, the, conformation of the syndecan-4 cytoplasmic domain itself is important in, the understanding of its biological roles. Gel filtration results show, that the syndecan-4 cytoplasmic domain (4L) itself forms a dimer, stabilized by ionic interactions between peptides at physiological pH., Commensurately, the NMR structures demonstrate that syndecan-4L is a, compact intertwined dimer with a symmetric clamp shape in the central, variable V region with a root-mean-square deviation between backbone atom, coordinates of 0.95 A for residues Leu(186)-Ala(195). The molecular, surface of the 4L dimer is highly positively charged. In addition, no, intersubunit NOEs in membrane proximal amino acid resides (C1 region) have, been observed, demonstrating that the C1 region is mostly unstructured in, the syndecan-4L dimer. Interestingly, two parallel strands of 4L form a, cavity in the center of the dimeric twist similar to our previously, reported 4V structure. The overall topology of the central variable region, within the 4L structure is very similar to that of 4V complexed with the, phosphatidylinositol 4,5-bisphosphate; however, the intersubunit, interaction mode is affected by the presence of C1 and C2 regions., Therefore, we propose that although the 4V region in the full cytoplasmic, domain has a tendency for strong peptide--peptide interaction, it may not, be enough to overcome the repulsion of the C1 regions of syndecan-4L.
About this Structure
1EJP is a Single protein structure of sequence from [1]. Full crystallographic information is available from OCA.
Reference
Solution structure of the dimeric cytoplasmic domain of syndecan-4., Shin J, Lee W, Lee D, Koo BK, Han I, Lim Y, Woods A, Couchman JR, Oh ES, Biochemistry. 2001 Jul 24;40(29):8471-8. PMID:11456484
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