Kinetic and thermodynamic characterization of the R17 coat protein-ribonucleic acid interaction. Journal Article uri icon



  • A filter retention assay is used to examine the kinetic and equilibrium properties of the interaction between phage R17 coat protein and its 21-nucleotide RNA binding site. The kinetics of the reaction are consistent with the equilibrium association constant and indicate a diffusion-controlled reaction. The temperature dependence of Ka gives delta H = -19 kcal/mol. This large favorable delta H is partially offset by a delta S = -30 cal mol-1 deg-1 to give a delta G = -11 kcal/mol at 2 degrees C in 0.19 M salt. The binding reaction has a pH optimum centered around pH 8.5, but pH has no effect on delta H. While the interaction is insensitive to the type of monovalent cation, the affinity decreases with the lyotropic series among monovalent anions. The ionic strength dependence of Ka reveals that ionic contacts contribute to the interaction. Most of the binding free energy, however, is a result of nonelectrostatic interactions.

publication date

  • May 24, 1983

has restriction

  • closed

Date in CU Experts

  • March 13, 2015 12:57 PM

Full Author List

  • Carey J; Uhlenbeck OC

author count

  • 2

Other Profiles

International Standard Serial Number (ISSN)

  • 0006-2960

Additional Document Info

start page

  • 2610

end page

  • 2615


  • 22


  • 11