Abstract
Oligomeric macromolecules in the cell self-organize into a wide variety of geometrical motifs such as helices, rings or linear filaments. The recombinase proteins involved in homologous recombination present many such assembly motifs. Here, we examine in particular the polymorphic characteristics of RecA, the most studied member of the recombinase family, using an integrative approach that relates local modes of monomer/monomer association to the global architecture of their screw-type organization. In our approach, local modes of association are sampled via docking or Monte Carlo simulations. This enables shedding new light on fiber morphologies that may be adopted by the RecA protein. Two distinct RecA helical morphologies, the so-called “extended” and “compressed” forms, are known to play a role in homologous recombination. We investigate the variability within each form in terms of helical parameters and steric accessibility. We also address possible helical discontinuities in RecA filaments due to multiple monomer-monomer association modes. By relating local interface organization to global filament morphology, the strategies developed here to study RecA self-assembly are particularly well suited to other DNA-binding proteins and to filamentous protein assemblies in general.
Highlights
The organization of biological objects as multimers, and as symmetric multimers, is the norm rather than the exception in cells
Before presenting our detailed results on fiber morphologies, we first discuss the known RecA assembly modes in order to justify the use of the rigid core region, and to place our explorations in context
Each pairwise interface geometry resulting from the docking simulation corresponds to a unique form of RecA oligomer assuming regular association. We examined these via Heligeom, which was employed to automatically characterize the geometry of the oligomers in terms of pitch, direction of rotation and number of monomers per turn, and to construct the corresponding fiber of arbitrary, specified length
Summary
The organization of biological objects as multimers, and as symmetric multimers, is the norm rather than the exception in cells. In an instructive review [1], Goodsell and Olson listed possible ways that proteins self-organize in cells and suggested why such association modes provide favorable options for proteins to exert their function. This type of organization, which incorporates the characteristics of a rigid body displacement, PLOS ONE | DOI:10.1371/journal.pone.0116414. An Integrative Approach to Explore Helix Morphologies and analysis, decision to publish, or preparation of the manuscript This type of organization, which incorporates the characteristics of a rigid body displacement, PLOS ONE | DOI:10.1371/journal.pone.0116414 March 18, 2015
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
