title: Role of 4.5S RNA in assembly of the bacterial signal recognition particle with its receptor.
abstract: The mechanism by which a signal recognition particle (SRP) and its receptor mediate protein targeting to the endoplasmic reticulum or to the bacterial plasma membrane is evolutionarily conserved. In Escherichia coli, this reaction is mediated by the Ffh/4.5S RNA ribonucleoprotein complex (Ffh/4.5S RNP; the SRP) and the FtsY protein (the SRP receptor). We have quantified the effects of 4.5S RNA on Ffh-FtsY complex formation by monitoring changes in tryptophan fluorescence. Surprisingly, 4.5S RNA facilitates both assembly and disassembly of the Ffh-FtsY complex to a similar extent. These results provide an example of an RNA molecule facilitating protein-protein interactions in a catalytic fashion.
authors.affiliation: Howard Hughes Medical Institute and Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94143, USA.
authors.forename: P
authors.initials: P
authors.lastname: Peluso
authors.forename: D
authors.initials: D
authors.lastname: Herschlag
authors.forename: S
authors.initials: S
authors.lastname: Nock
authors.forename: D M
authors.initials: DM
authors.lastname: Freymann
authors.forename: A E
authors.initials: AE
authors.lastname: Johnson
authors.forename: P
authors.initials: P
authors.lastname: Walter
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D002384:Catalysis; D004926:Escherichia coli / Q000378:metabolism; D029968:Escherichia coli Proteins; D006153:Guanosine Diphosphate / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism; D006165:Guanylyl Imidodiphosphate / Q000378:metabolism; D007700:Kinetics; D008956:Models, Chemical; D009690:Nucleic Acid Conformation; D011485:Protein Binding; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D012329:RNA, Bacterial / Q000737:chemistry / Q000378:metabolism*; D018160:Receptors, Cytoplasmic and Nuclear / Q000737:chemistry / Q000378:metabolism*; D012261:Ribonucleoproteins / Q000737:chemistry / Q000378:metabolism; D018271:Signal Recognition Particle / Q000737:chemistry / Q000378:metabolism*; D013050:Spectrometry, Fluorescence; D013816:Thermodynamics; D014364:Tryptophan
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; C082931:Ffh protein, E coli; C087406:FtsY protein, Bacteria; D012329:RNA, Bacterial; D018160:Receptors, Cytoplasmic and Nuclear; D012261:Ribonucleoproteins; D018271:Signal Recognition Particle; D006153:Guanosine Diphosphate; D006165:Guanylyl Imidodiphosphate; D006160:Guanosine Triphosphate; D014364:Tryptophan