Exploring subdomain cooperativity in T4 lysozyme I: structural and energetic studies of a circular permutant and protein fragment.

ABSTRACT: Small proteins are generally observed to fold in an apparent two-state manner. Recently, however, more sensitive techniques have demonstrated that even seemingly single-domain proteins are actually made up of smaller subdomains. T4 lysozyme is one such protein. We explored the relative autonomy of its two individual subdomains and their contribution to the overall stability of T4 lysozyme by examining a circular permutation (CP13*) that relocates the N-terminal A-helix, creating subdomains that are contiguous in sequence. By determining the high-resolution structure of CP13* and characterizing its energy landscape using native state hydrogen exchange (NSHX), we show that connectivity between the subdomains is an important determinant of the energetic cooperativity but not structural integr

SUBMITTER: Cellitti J 

PROVIDER: S-EPMC2206633 | biostudies-literature | 2007 May

REPOSITORIES: biostudies-literature