4RBV

PduA K26A S40GSG mutant, from Salmonella enterica serovar Typhimurium LT2

Summary for 4RBV

• Entry DOI: 10.2210/pdb4rbv/pdb
• Related: 4RBT 4RBU
• Descriptor: Propanediol utilization protein PduA, SULFATE ION (3 entities in total)
• Functional Keywords: bacterial microcompartment shell protein, structural protein
• Biological source: Salmonella enterica serovar Typhimurium
• Total number of polymer chains: 7
• Total formula weight: 73711.46

Authors

Chun, S.,Sawaya, M.R.,Yeates, T.O. (deposition date: 2014-09-13, release date: 2015-02-18, Last modification date: 2024-02-28)

Primary citation

Chowdhury, C.,Chun, S.,Pang, A.,Sawaya, M.R.,Sinha, S.,Yeates, T.O.,Bobik, T.A.
Selective molecular transport through the protein shell of a bacterial microcompartment organelle.
Proc.Natl.Acad.Sci.USA, 112:2990-2995, 2015

PubMed Abstract: Bacterial microcompartments are widespread prokaryotic organelles that have important and diverse roles ranging from carbon fixation to enteric pathogenesis. Current models for microcompartment function propose that their outer protein shell is selectively permeable to small molecules, but whether a protein shell can mediate selective permeability and how this occurs are unresolved questions. Here, biochemical and physiological studies of structure-guided mutants are used to show that the hexameric PduA shell protein of the 1,2-propanediol utilization (Pdu) microcompartment forms a selectively permeable pore tailored for the influx of 1,2-propanediol (the substrate of the Pdu microcompartment) while restricting the efflux of propionaldehyde, a toxic intermediate of 1,2-propanediol catabolism. Crystal structures of various PduA mutants provide a foundation for interpreting the observed biochemical and phenotypic data in terms of molecular diffusion across the shell. Overall, these studies provide a basis for understanding a class of selectively permeable channels formed by nonmembrane proteins.

PubMed: 25713376
DOI: 10.1073/pnas.1423672112

Experimental method

X-RAY DIFFRACTION (3.1 Å)