title: A bacterial global regulator forms a prion.
abstract: Prions are self-propagating protein aggregates that act as protein-based elements of inheritance in fungi. Although prevalent in eukaryotes, prions have not been identified in bacteria. Here we found that a bacterial protein, transcription terminator Rho of Clostridium botulinum (Cb-Rho), could form a prion. We identified a candidate prion-forming domain (cPrD) in Cb-Rho and showed that it conferred amyloidogenicity on Cb-Rho and could functionally replace the PrD of a yeast prion-forming protein. Furthermore, its cPrD enabled Cb-Rho to access alternative conformations in Escherichia coli-a soluble form that terminated transcription efficiently and an aggregated, self-propagating prion form that was functionally compromised. The prion form caused genome-wide changes in the transcriptome. Thus, Cb-Rho functions as a protein-based element of inheritance in bacteria, suggesting that the emergence of prions predates the evolutionary split between eukaryotes and bacteria.
authors.affiliation: Department of Microbiology and Immunobiology, Harvard Medical School, 4 Blackfan Circle, Boston, MA 02115, USA.
authors.forename: Andy H
authors.initials: AH
authors.lastname: Yuan
authors.affiliation: Department of Microbiology and Immunobiology, Harvard Medical School, 4 Blackfan Circle, Boston, MA 02115, USA. ann_hochschild@hms.harvard.edu.
authors.forename: Ann
authors.initials: A
authors.lastname: Hochschild
mesh_terms: D000595:Amino Acid Sequence; D000682:Amyloid / Q000737:chemistry / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D003014:Clostridium botulinum / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism; D019143:Evolution, Molecular; D011328:Prions / Q000378:metabolism*; D000072417:Protein Domains; D012234:Rho Factor / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D000682:Amyloid; D001426:Bacterial Proteins; D011328:Prions; D012234:Rho Factor; D029701:Saccharomyces cerevisiae Proteins