1u9p

Publication Abstract from PubMed

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.

Consolidating critical binding determinants by noncyclic rearrangement of protein secondary structure.,Tabtiang RK, Cezairliyan BO, Grant RA, Cochrane JC, Sauer RT Proc Natl Acad Sci U S A. 2005 Feb 15;102(7):2305-9. Epub 2005 Feb 2. PMID:15689399^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.