Specific DNA Binding to CRP Induces Conformational Changes in the CRP and the DNA in Solution: A Small-Angle Neutron Scattering Study

Published

October 12, 2021

Author(s)

Susan T. Krueger, S. K. Gregurick, Y. Shi, S. Wang, B Waldkowski, Frederick P. Schwarz

Abstract

The transcription activator, 3'-5' cyclic adenosine monophosphate (cAMP) receptor protein (CRP), when ligated with cAMP, activates the transcription of over 25 operons, which code for enzymes involved in carbohydrate metabolism in E. coli. Small-angle neutron scattering measurements on complexes of cAMP-ligated CRP with 40 base pair (bp) DNA duplexes containing the 22 bp consensus sequence and the lac promoter sequence of the CRP binding site show that the radius of gyration of the complex increases to about 28 from 22 in the absence of bound DNA. Similar increases are also observed for complexes of a T128->L/S128->A double mutant and of a cAMP-ligated T128->L mutant of CRP bound to the consensus DNA duplex. Monte Carlo simulations of the scattered intensities as a function of the wavevector transfer from energy-minimization of the x-ray crystal structure of cAMP-ligated CRP-DNA complex indicate that the increase arises out of a displacement of the amino-terminal domain of CRP. This could have implications in the mechanism for the activation of transcription by CRP since the amino-terminal domain contains a contact point for interacting with RNA polymerase.

Citation

Science

Pub Type

Journals

Keywords

DNA, energy minimization, promoter conformation, protein, small angle neutron scattering, x-ray structure

Citation

Krueger, S. , Gregurick, S. , Shi, Y. , Wang, S. , Waldkowski, B. and Schwarz, F. (2021), Specific DNA Binding to CRP Induces Conformational Changes in the CRP and the DNA in Solution: A Small-Angle Neutron Scattering Study, Science (Accessed January 22, 2025)