From genetic to structural characterization of a new class of RNA-binding domain within the SacY/BglG family of antiterminator proteins.
Manival, X., Yang, Y., Strub, M.P., Kochoyan, M., Steinmetz, M., Aymerich, S.(1997) EMBO J 16: 5019-5029
- PubMed: 9305643
- DOI: https://doi.org/10.1093/emboj/16.16.5019
- Primary Citation of Related Structures:
1AUU - PubMed Abstract:
SacY is the prototype of a family of regulatory proteins able to prevent transcription termination. It interacts with a 29 nucleotide RNA sequence able to fold into a stem-loop structure and partially overlapping with a terminator sequence located in the 5' leader mRNA region of the gene it controls. We show here that the N-terminal fragment of SacY, SacY(1-55), and the corresponding fragments of other members of the family have antiterminator activities with efficiency and specificity identical to those of the full-length proteins. In vitro, this activity correlates with the specific affinity of SacY(1-55) for its RNA target. UV melting experiments demonstrate that SacY(1-55) binding stabilizes the RNA target structure. The NMR solution structure of SacY(1-55) is very similar to that obtained in the crystal (van Tilbeurgh et al., 1997): the peptide is folded as a symmetrical dimer without any structural homology with other RNA-binding domains yet characterized. According to a preliminary NMR analysis of the SacY(1-55)-RNA complex, the protein dimer is not disrupted upon RNA binding and several residues implicated in RNA recognition are located at the edge of the dimer interface. This suggests a new mode of protein-RNA interaction.
Organizational Affiliation:
CBS, Faculté de Pharmacie, CNRS-UMR9955, INSERM-U414, Université Montpellier, France.