Binding sites of the 19-kDa and 68/72-kDa signal recognition particle (SRP) proteins on SRP RNA as determined in protein-RNA "footprinting".
- 1 March 1988
- journal article
- research article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences
- Vol. 85 (6) , 1801-1805
- https://doi.org/10.1073/pnas.85.6.1801
Abstract
We have used the nuclease alpha-sarcin to map the binding sites of the 19-kDa and the 68/72-kDa proteins of signal recognition particle (SRP) on SRP RNA. We found that the regions of protection to nuclease afforded by the two proteins were distinct. p19 protected primarily the two tips in the RNA secondary structure. p68/72 protected a large region extending across the center of the particle and altered the nuclease pattern in the regions that p19 would bind, suggesting that these two proteins may be in close proximity in the particle. The protection afforded by the two proteins in combination was equal to the sum of the individual protections. We have not observed cooperativity in the binding of these two proteins as assessed by the protection assay; nor do we have any evidence that the structure becomes more compact as it assembles. The map derived from this "footprint" analysis places the signal recognition domain (p54 bound to the RNA via the 19-kDa protein) and the elongation arrest domain (associated with the Alu end of the particle) on opposite ends of the particle. Thus, it is possible that SRP recognizes signals by the direct interaction of p54 with the signal sequence at the nascent chain exit site and simultaneously blocks elongation by the entrance of p9/14 into the aminoacyl tRNA site 16 nm away.This publication has 20 references indexed in Scilit:
- The signal sequence of nascent preprolactin interacts with the 54K polypeptide of the signal recognition particleNature, 1986
- The secondary structure of the 7SL RNA in the signal recognition particle: functional implicationsNucleic Acids Research, 1985
- Elongation arrest is not a prerequisite for secretory protein translocation across the microsomal membrane.The Journal of cell biology, 1985
- Structure of the signal recognition particle by electron microscopy.Proceedings of the National Academy of Sciences, 1985
- Structure and evolution of the 7SL RNA component of the signal recognition particle.The EMBO Journal, 1984
- Protein translocation across the endoplasmic reticulumCell, 1984
- Disassembly and reconstitution of signal recognition particleCell, 1983
- Nascent polypeptide chains exit the ribosome in the same relative position in both eucaryotes and procaryotes.The Journal of cell biology, 1983
- Signal recognition particle contains a 7S RNA essential for protein translocation across the endoplasmic reticulumNature, 1982
- Site specific enzymatic cleavage of RNANucleic Acids Research, 1979