[SCAN] A hierarchical cascade of protein-protein cross-linking involved in the assembly of the spore surface layers

Title: A hierarchical cascade of protein-protein cross-linking involved in the assembly of the spore surface layers

Speaker: Adriano Henriques

Abstract: The surface of Bacillus subtilis spores is formed by the ordered synthesis and localisation of over 80 proteins that self-assemble to form an inner and an outer coat, and a more external crust. The proteins that form the coat/crust are produced in the mother cell, one of the two cells that cooperate in spore differentiation, and targeted to the surface of the developing spore. The localisation of the coat/crust structural components is guided by a group of so-called morphogenetic proteins. The assembly process, however, is further governed by post-translational modifications thought to enforce the right pattern of protein-protein interactions. We will show how a morphogenetic protein that serves as the inner coat hub cooperates with a protein-protein cross-linking enzyme and a protease to ensure fidelity of the assembly process. 

With a few exceptions, the spore surface proteins are not conserved among sporeformers, as they reflect the niche where spores are formed and their interactions with the immediate environment. Yet, the morphogenetic proteins tend to be conserved and thus, general principles governing the macromolecular assembly process can be derived from studies in model organisms such as B. subtilis.