The Structure of the Coliphage Hk022 Nun Protein-Lambda-Phage Boxb RNA Complex. Implications for the Mechanism of Transcription TerminationFaber, C., Schaerpf, M., Becker, T., Sticht, H., Roesch, P.
(2001) J.Biol.Chem. 276: 32064
- PubMed: 11356847
- DOI: 10.1074/jbc.M102975200
- PubMed Abstract:
- Antitermination in Bacteriophage Lambda: The Structure of the N36 Peptide-Boxb RNA Complex
Schaerpf, M.,Sticht, H.,Schweimer, K.,Boehm, M.,Hoffmann, S.,Roesch, P.
(2000) Eur.J.Biochem. 267: 2397
Nun protein from coliphage HK022 binds to phage boxB RNA and functions, in contrast to phage lambda N protein, as a transcriptional terminator. The basic Nun-(10-44) peptide contains the boxB RNA binding arginine rich motif, ARM. The peptide binds bo ...
Nun protein from coliphage HK022 binds to phage boxB RNA and functions, in contrast to phage lambda N protein, as a transcriptional terminator. The basic Nun-(10-44) peptide contains the boxB RNA binding arginine rich motif, ARM. The peptide binds boxB RNA and competes with the phage lambda ARM peptide N-(1-36) as indicated by nuclear magnetic resonance (NMR) spectroscopy titrations. In two-dimensional nuclear Overhauser enhancement spectroscopy experiments boxB RNA in complex with Nun-(20-44) exhibits the same pattern of resonances as it does in complex with N peptides containing the ARM, and we could show that Nun-(20-44) forms a bent alpha-helix upon binding to the boxB RNA. The structure of the boxB RNA-bound Nun-(20-44) was determined on the basis of 191 intra- and 30 intermolecular distance restraints. Ser-24 is anchored to the lower RNA stem, and stacking of Tyr-39 and A7 is clearly experimentally indicated. Arg-28 shows numerous contacts to the RNA stem. Leu-22, Ile-30, Trp-33, Ile-37, and Leu-41 form a hydrophobic surface, which could be a recognition site for additional host factors such as NusG. Such a hydrophobic surface area is not present in N-(1-36) bound to boxB RNA.
Lehrstuhl für Biopolymere, Universität Bayreuth, Universitätsstr. 30, 95440 Bayreuth, Germany.