The d'--d--d' vertical triad is less discriminating than the a'--a--a' vertical triad in the antiparallel coiled-coil dimer motif.

ABSTRACT: Elucidating relationships between the amino-acid sequences of proteins and their three-dimensional structures, and uncovering non-covalent interactions that underlie polypeptide folding, are major goals in protein science. One approach toward these goals is to study interactions between selected residues, or among constellations of residues, in small folding motifs. The α-helical coiled coil has served as a platform for such studies because this folding unit is relatively simple in terms of both sequence and structure. Amino acid side chains at the helix-helix interface of a coiled coil participate in so-called "knobs-into-holes" (KIH) packing whereby a side chain (the knob) on one helix inserts into a space (the hole) generated by four side chains on a partner helix. The vast majority of

SUBMITTER: Steinkruger JD 

PROVIDER: S-EPMC3319448 | biostudies-literature | 2012 Feb

REPOSITORIES: biostudies-literature