Helix capping in the GCN4 leucine zipper. Export

@article{citeulike:2148689, abstract = {Capping interactions associated with specific sequences at or near the ends of alpha-helices are important determinants of the stability of protein secondary and tertiary structure. We investigate here the role of the helix-capping motif Ser-X-X-Glu, a sequence that occurs frequently at the N termini of alpha helices in proteins, on the conformation and stability of the GCN4 leucine zipper. The 1.8 A resolution crystal structure of the capped molecule reveals distinct conformations, packing geometries and hydrogen-bonding networks at the amino terminus of the two helices in the leucine zipper dimer. The free energy of helix stabilization associated with the hydrogen-bonding and hydrophobic interactions in this capping structure is -1.2 kcal/mol, evaluated from thermal unfolding experiments. A single cap thus contributes appreciably to stabilizing the terminated helix and thereby the native state. These results suggest that helix capping plays a further role in protein folding, providing a sensitive connector linking alpha-helix formation to the developing tertiary structure of a protein.}, address = {Department of Biochemistry, Weill Medical College of Cornell University, New York, NY, 10021, USA.}, author = {Lu, M. and Shu, W. and Ji, H. and Spek, E. and Wang, L. and Kallenbach, N. R.}, citeulike-article-id = {2148689}, citeulike-linkout-0 = {http://dx.doi.org/10.1006/jmbi.1999.2707}, citeulike-linkout-1 = {http://view.ncbi.nlm.nih.gov/pubmed/10329176}, citeulike-linkout-2 = {http://www.hubmed.org/display.cgi?uids=10329176}, day = {14}, doi = {10.1006/jmbi.1999.2707}, issn = {0022-2836}, journal = {J Mol Biol}, month = {May}, number = {4}, pages = {743--752}, posted-at = {2007-12-19 22:15:23}, priority = {2}, title = {Helix capping in the GCN4 leucine zipper.}, url = {http://dx.doi.org/10.1006/jmbi.1999.2707}, volume = {288}, year = {1999} }

TY - JOUR ID - citeulike:2148689 L3 - citeulike-article-id:2148689 N2 - Capping interactions associated with specific sequences at or near the ends of alpha-helices are important determinants of the stability of protein secondary and tertiary structure. We investigate here the role of the helix-capping motif Ser-X-X-Glu, a sequence that occurs frequently at the N termini of alpha helices in proteins, on the conformation and stability of the GCN4 leucine zipper. The 1.8 A resolution crystal structure of the capped molecule reveals distinct conformations, packing geometries and hydrogen-bonding networks at the amino terminus of the two helices in the leucine zipper dimer. The free energy of helix stabilization associated with the hydrogen-bonding and hydrophobic interactions in this capping structure is -1.2 kcal/mol, evaluated from thermal unfolding experiments. A single cap thus contributes appreciably to stabilizing the terminated helix and thereby the native state. These results suggest that helix capping plays a further role in protein folding, providing a sensitive connector linking alpha-helix formation to the developing tertiary structure of a protein. IS - 4 JF - J Mol Biol SN - 0022-2836 AD - Department of Biochemistry, Weill Medical College of Cornell University, New York, NY, 10021, USA. EP - 752 TI - Helix capping in the GCN4 leucine zipper. VL - 288 SP - 743 AU - Lu, M AU - Shu, W AU - Ji, H AU - Spek, E AU - Wang, L AU - Kallenbach, NR PY - 1999/05/14/ UR - http://dx.doi.org/10.1006/jmbi.1999.2707 ER -