4RBU: Pdua K26a S40q Mutant, From Salmonella Enterica Serovar Typhimurium Lt2

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.
PDB ID: 4RBUDownload
MMDB ID: 127115
PDB Deposition Date: 2014/9/13
Updated in MMDB: 2015/03
Experimental Method:
x-ray diffraction
Resolution: 2.79  Å
Source Organism:
Similar Structures:
Biological Unit for 4RBU: hexameric; determined by author and by software (PISA)
Molecular Components in 4RBU
Label Count Molecule
Proteins (6 molecules)
Propanediol Utilization Protein Pdua(Gene symbol: pduA)
Molecule annotation
Chemicals (8 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB