Internal dynamics of the tryptophan repressor (TrpR) and two functionally distinct TrpR variants, L75F-TrpR and A77V-TrpR, in their l-Trp-bound forms.

ABSTRACT: Backbone amide dynamics of the Escherichia coli tryptophan repressor protein (WT-TrpR) and two functionally distinct variants, L75F-TrpR and A77V-TrpR, in their holo (l-tryptophan corepressor-bound) form have been characterized using (15)N nuclear magnetic resonance (NMR) relaxation. The three proteins possess very similar structures, ruling out major conformational differences as the source of their functional differences, and suggest that changes in protein flexibility are at the origin of their distinct functional properties. Comparison of site specific (15)N-T(1), (15)N-T(2), (15)N-{(1)H} nuclear Overhauser effect, reduced spectral density, and generalized order (S(2)) parameters indicates that backbone dynamics in the three holo-repressors are overall very similar with a few notable a

SUBMITTER: Tripet BP 

PROVIDER: S-EPMC3113449 | biostudies-literature | 2011 Jun

REPOSITORIES: biostudies-literature