Selective molecular transport through the protein shell of a bacterial microcompartment organelle
- Iowa State Univ., Ames, IA (United States). Roy J. Carver Dept. of Biochemistry, Biophysics, and Molecular Biology
- Univ. of California, Los Angeles, CA (United States). Molecular Biology Inst.
- Univ. of California, Los Angeles, CA (United States). UCLA-DOE Inst. for Genomics and Proteomics
- Univ. of California, Los Angeles, CA (United States). Molecular Biology Inst. UCLA-DOE Inst. for Genomics and Proteomics. Dept. of Chemistry and Biochemistry
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. In this paper, 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. Finally and overall, these studies provide a basis for understanding a class of selectively permeable channels formed by nonmembrane proteins.
- Research Organization:
- Iowa State Univ., Ames, IA (United States); Univ. of California, Los Angeles, CA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Biological and Environmental Research (BER); National Inst. of Health (NIH) (United States)
- Grant/Contract Number:
- AC02-06CH11357; 5P41RR015301-10; 8 P41 GM103403-10; R01AI081146; T32-GM008496
- OSTI ID:
- 1172992
- Journal Information:
- Proceedings of the National Academy of Sciences of the United States of America, Vol. 112, Issue 10; ISSN 0027-8424
- Publisher:
- National Academy of Sciences, Washington, DC (United States)Copyright Statement
- Country of Publication:
- United States
- Language:
- ENGLISH
Web of Science
Similar Records
Alanine Scanning Mutagenesis Identifies an Asparagine–Arginine–Lysine Triad Essential to Assembly of the Shell of the Pdu Microcompartment
Self-assembling Shell Proteins PduA and PduJ have Essential and Redundant Roles in Bacterial Microcompartment Assembly