Binding by TRBP-dsRBD2 Does Not Induce Bending of Double-Stranded RNA.

ABSTRACT: Protein-nucleic acid interactions are central to a variety of biological processes, many of which involve large-scale conformational changes that lead to bending of the nucleic acid helix. Here, we focus on the nonsequence-specific protein TRBP, whose double-stranded RNA-binding domains (dsRBDs) interact with the A-form geometry of double-stranded RNA (dsRNA). Crystal structures of dsRBD-dsRNA interactions suggest that the dsRNA helix must bend in such a way that its major groove expands to conform to the dsRBD's binding surface. We show through isothermal titration calorimetry experiments that dsRBD2 of TRBP binds dsRNA with a temperature-independent observed binding affinity (KD ∼500 nM). Furthermore, a near-zero observed heat capacity change (ΔCp = 70 ± 40 cal·mol(-1)·K(-1)) suggests th

SUBMITTER: Acevedo R 

PROVIDER: S-EPMC4919420 | biostudies-literature | 2016 Jun

REPOSITORIES: biostudies-literature