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10:52
Sample Preparation for Mass Spectrometry-based Identification of RNA-binding Regions
Published on: September 28, 2017
Bruno protein contains an expanded RNA recognition motif
Angeline M Lyon1, Brad S Reveal, Paul M Macdonald
1Department of Chemistry and Biochemistry, University of Texas, Austin, Texas 78712, USA.
Biochemistry
|November 19, 2009
Summary
The expanded RNA recognition motif (RRM) in Drosophila Bruno protein shows decreased RNA binding affinity upon N-terminal deletion. This study reveals key features important for RNA recognition by RRM-containing proteins.
Area of Science:
- Molecular Biology
- Structural Biology
- Genetics
Background:
- The RNA recognition motif (RRM) is a common RNA-binding domain found in ~2% of human proteins.
- Bruno protein in Drosophila utilizes an expanded RRM to bind regulatory elements in oskar mRNA, controlling translation.
Purpose of the Study:
- To characterize the expanded RRM of the Drosophila Bruno protein.
- To investigate the structural and functional impact of N-terminal amino acids on RRM RNA-binding activity.
Main Methods:
- Nuclear Magnetic Resonance (NMR) spectroscopy was used to determine the structure of the Bruno RRM.
- RNA-binding affinity was assessed by deleting N-terminal amino acids.
Main Results:
- The expanded Bruno RRM maintains the canonical RRM fold (four beta-strands, two alpha-helices) with an additional N-terminal loop.
- Deletion of 40 N-terminal amino acids significantly reduced RNA-binding affinity.
- A truncated RRM lacking flexible N-terminal residues formed a stable, canonical RRM fold, indicating the fold itself was not disrupted.
Conclusions:
- The expanded N-terminus of the Bruno RRM, including a flexible loop, is crucial for high-affinity RNA binding.
- This study provides insights into the structural determinants of RNA recognition by RRM domains.
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