Buried polar residues in coiled-coil interfaces.Akey, D.L., Malashkevich, V.N., Kim, P.S.
(2001) Biochemistry 40: 6352-6360
- PubMed: 11371197
- Primary Citation of Related Structures:
- PubMed Abstract:
- X-ray structure of the GCN4 leucine zipper, a two-stranded, parallel coiled coil.
O'Shea, E.K.,Klemm, J.D.,Kim, P.S.,Alber, T.
(1991) Science 254: 539
- A switch between two-, three-, and four-stranded coiled coils in GCN4 leucine zipper mutants
Harbury, P.B.,Zhang, T.,Kim, P.S.,Alber, T.
(1993) Science 262: 1401
- Buried polar residues and structural specificity in the GCN4 leucine zipper
Gonzalez Jr., L.,Woolfson, D.N.,Alber, T.
(1996) Nat.Struct.Mol.Biol. 3: 1011
Coiled coils, estimated to constitute 3-5% of the encoded residues in most genomes, are characterized by a heptad repeat, (abcdefg)(n), where the buried a and d positions form the interface between multiple alpha-helices. Although generally hydrophob ...
Coiled coils, estimated to constitute 3-5% of the encoded residues in most genomes, are characterized by a heptad repeat, (abcdefg)(n), where the buried a and d positions form the interface between multiple alpha-helices. Although generally hydrophobic, a substantial fraction ( approximately 20%) of these a- and d-position residues are polar or charged. We constructed variants of the well-characterized coiled coil GCN4-p1 with a single polar residue (Asn, Gln, Ser, or Thr) at either an a or a d position. The stability and oligomeric specificity of each variant were measured, and crystal structures of coiled-coil trimers with threonine or serine at either an a or a d position were determined. The structures show how single polar residues in the interface affect not only local packing, but also overall coiled-coil geometry as seen by changes in the Crick supercoil parameters and core cavity volumes.
Howard Hughes Medical Institute, Whitehead Institute for Biomedical Research, Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA.