Dynamic Transmission of Protein Allostery without Structural Change: Spatial Pathways or Global Modes?
We examine the contrast between mechanisms for allosteric signaling that involve structural change, and those that do not, from the perspective of allosteric pathways. In particular we treat in detail the case of fluctuation-allostery by which amplitude modulation of the thermal fluctuations of the elastic normal modes conveys the allosteric signal, and address the question of what an allosteric pathway means in this case. We find that a perturbation theory of thermal elastic solids and nonperturbative approach (by super-coarse-graining elasticity into internal bending modes) have opposite signatures in their structure of correlated pathways. We illustrate the effect from analysis of previous results from GlxR of Corynebacterium glutamicum, an example of the CRP/FNR transcription family of allosteric homodimers. We find that the visibility of both correlated pathways and disconnected sites of correlated motion in this protein suggests that mechanisms of local elastic stretch and bend are recruited for the purpose of creating and controlling allosteric cooperativity.
Biophysical Sciences Institute, Durham University, Durham, United Kingdom; Department of Physics, Durham University, Durham, United Kingdom. Electronic address: t.c.b.mcleish@durham.ac.uk.
Tom C B
TC
McLeish
Biophysical Sciences Institute, Durham University, Durham, United Kingdom; School of Biological and Biomedical Sciences, Durham University, Durham, United Kingdom.
Martin J
MJ
Cann
School of Chemical Engineering and Analytical Sciences, University of Manchester, Manchester, United Kingdom.
Thomas L
TL
Rodgers
D000494:Allosteric Regulation; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D003198:Computer Simulation; D048230:Corynebacterium glutamicum; D019281:Dimerization; D004548:Elasticity; D008958:Models, Molecular; D009154:Mutation
D001426:Bacterial Proteins