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A threefold RNA-protein interface in the signal recognition particle gates native complex assembly
Tuhin Subhra Maity1, Kevin M Weeks
1Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599-3290, USA.
Journal of Molecular Biology
|April 17, 2007
Summary
Transient intermediates in ribonucleoprotein assembly can lead to misassembly. The order of protein and RNA interactions is critical for correct signal recognition particle formation and cellular function.
Area of Science:
- Molecular Biology
- Biochemistry
- Structural Biology
Background:
- Transient structural intermediates are crucial in RNA and protein folding.
- The role of these intermediates in multi-component ribonucleoprotein (RNP) assembly and misassembly is understudied.
Purpose of the Study:
- To investigate the role of transient intermediates in signal recognition particle (SRP) assembly.
- To understand how the order of component binding affects RNP formation and potential misassembly.
Main Methods:
- Studied the assembly of SRP19 protein with SRP RNA.
- Investigated the effect of SRP54 protein binding on SRP19-RNA complex formation.
- Analyzed the structural consequences of altered assembly order.
Main Results:
- SRP54 binding during SRP19-RNA assembly creates a non-native folding pathway.
- SRP54 can bind to an assembly intermediate, interfering with proper loop folding.
- An incorrect temporal assembly order leads to aberrant three-component RNP particles.
Conclusions:
- The order of component addition is critical for correct RNP assembly.
- Misassembly can occur if binding partners interact with intermediates prematurely.
- Spatial or temporal compartmentalization may be necessary to regulate RNP assembly in cells.
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