Download MendeleyConsolidating critical binding determinants by noncyclic rearrangement of protein secondary structure
Tabtiang, R.K., Cezairliyan, B.O., Grant, R.A., Cochrane, J.C., Sauer, R.T.(2005) Proc Natl Acad Sci U S A 102: 2305-2309
- PubMed: 15689399
- DOI: https://doi.org/10.1073/pnas.0409562102
- Primary Citation of Related Structures:
1U9P - PubMed Abstract:
We designed a single-chain variant of the Arc repressor homodimer in which the beta strands that contact operator DNA are connected by a hairpin turn and the alpha helices that form the tetrahelical scaffold of the dimer are attached by a short linker. The designed protein represents a noncyclic permutation of secondary structural elements in another single-chain Arc molecule (Arc-L1-Arc), in which the two subunits are fused by a single linker. The permuted protein binds operator DNA with nanomolar affinity, refolds on the sub-millisecond time scale, and is as stable as Arc-L1-Arc. The crystal structure of the permuted protein reveals an essentially wild-type fold, demonstrating that crucial folding information is not encoded in the wild-type order of secondary structure. Noncyclic rearrangement of secondary structure may allow grouping of critical active-site residues in other proteins and could be a useful tool for protein design and minimization.
Organizational Affiliation:
Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
