Structural principles that enable oligomeric small heat-shock protein paralogs to evolve distinct functions

We report how coassembly is avoided by two oligomeric small heat-shock protein paralogs. A hierarchy of assembly, involving intermediates that are populated only fleetingly at equilibrium, ensures selective oligomerization. Conformational flexibility at noninterfacial regions in the monomers prevents coassembly, allowing interfaces to remain largely conserved. Homomeric oligomers must overcome the entropic benefit of coassembly and, accordingly, homomeric paralogs comprise fewer subunits than homomers that have no paralogs.

Source: ScienceNOW - February 22, 2018 Category: Science Authors: Hochberg, G. K. A., Shepherd, D. A., Marklund, E. G., Santhanagoplan, I., Degiacomi, M. T., Laganowsky, A., Allison, T. M., Basha, E., Marty, M. T., Galpin, M. R., Struwe, W. B., Baldwin, A. J., Vierling, E., Benesch, J. L. P. Tags: Biochemistry reports Source Type: news