Molecular simulations unravel the molecular principles that mediate selective permeability of carboxysome shell protein.

ABSTRACT: Bacterial microcompartments (BMCs) are nanoscale proteinaceous organelles that encapsulate enzymes from the cytoplasm using an icosahedral protein shell that resembles viral capsids. Of particular interest are the carboxysomes (CBs), which sequester the CO₂-fixing enzymes ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) to enhance carbon assimilation. The carboxysome shell serves as a semi-permeable barrier for passage of metabolites in and out of the carboxysome to enhance CO₂ fixation. How the protein shell directs influx and efflux of molecules in an effective manner has remained elusive. Here we use molecular dynamics and umbrella sampling calculations to determine the free-energy profiles of the metabolic substrates, bicarbonate, CO₂ and ribul

SUBMITTER: Faulkner M 

PROVIDER: S-EPMC7562746 | biostudies-literature | 2020 Oct

REPOSITORIES: biostudies-literature