The structure of a fibril-forming sequence, NNQQNY, in the context of a globular fold.

ABSTRACT: Numerous human disorders are associated with the formation of protein fibrils. The fibril-forming capacity of a protein has been found in recent studies to be determined by a short segment of residues that forms a dual beta-sheet, called a steric zipper, in the spine of the fibril. The question arises as to whether a fibril-forming segment, when inserted within the sequence of a globular protein, will invariably cause the protein to form fibrils. Here we investigate this question by inserting the known fibril-forming segment NNQQNY into the globular enzyme, T7 endonuclease I. From earlier studies, we know that in its fibril form, NNQQNY is in an extended conformation. We first found that the inserted NNQQNY stimulates fibril formation of T7 endonuclease I in solution. Thus NNQQNY within T7

SUBMITTER: Guo Z 

PROVIDER: S-EPMC2525518 | biostudies-literature | 2008 Sep

REPOSITORIES: biostudies-literature