Direct observation in solution of a preexisting structural equilibrium for a mutant of the allosteric aspartate transcarbamoylase.

ABSTRACT: Many signaling and metabolic pathways rely on the ability of some of the proteins involved to undergo a substrate-induced transition between at least two structural states. Among the various models put forward to account for binding and activity curves of those allosteric proteins, the Monod, Wyman, and Changeux model for allostery theory has certainly been the most influential, although a central postulate, the preexisting equilibrium between the low-activity, low-affinity quaternary structure and the high-activity, high-affinity quaternary structure states in the absence of substrates, has long awaited direct experimental substantiation. Upon substrate binding, allosteric Escherichia coli aspartate transcarbamoylase adopts alternate quaternary structures, stabilized by a set of interdoma

SUBMITTER: Fetler L 

PROVIDER: S-EPMC1766413 | biostudies-literature | 2007 Jan

REPOSITORIES: biostudies-literature