Selective Permeability of Carboxysome Shell Pores to Anionic Molecules.

ABSTRACT: Carboxysomes are closed polyhedral cellular microcompartments that increase the efficiency of carbon fixation in autotrophic bacteria. Carboxysome shells consist of small proteins that form hexameric units with semipermeable central pores containing binding sites for anions. This feature is thought to selectively allow access to RuBisCO enzymes inside the carboxysome by HCO₃^- (the dominant form of CO₂ in the aqueous solution at pH 7.4) but not O₂, which leads to a nonproductive reaction. To test this hypothesis, here we use molecular dynamics simulations to characterize the energetics and permeability of CO₂, O₂, and HCO₃^- through the central pores of two different shell proteins, namely, CsoS1A of α-ca

SUBMITTER: Mahinthichaichan P 

PROVIDER: S-EPMC6311388 | biostudies-literature | 2018 Oct

REPOSITORIES: biostudies-literature