Structural characterization of an engineered tandem repeat contrasts the importance of context and sequence in protein folding.

ABSTRACT: To test a different approach to understanding the relationship between the sequence of part of a protein and its conformation in the overall folded structure, the amino acid sequence corresponding to an alpha-helix of T4 lysozyme was duplicated in tandem. The presence of such a sequence repeat provides the protein with "choices" during folding. The mutant protein folds with almost wild-type stability, is active, and crystallizes in two different space groups, one isomorphous with wild type and the other with two molecules in the asymmetric unit. The fold of the mutant is essentially the same in all cases, showing that the inserted segment has a well-defined structure. More than half of the inserted residues are themselves helical and extend the helix present in the wild-type protein. Parti

SUBMITTER: Sagermann M 

PROVIDER: S-EPMC26838 | biostudies-literature | 1999 May

REPOSITORIES: biostudies-literature