Compensatory mutations in the L30e kink-turn RNA-protein complex

Area of Science:

• Molecular Biology
• Structural Biology
• Genetics

Background:

• The Saccharomyces cerevisiae ribosomal protein L30e autoregulates its own gene expression.
• L30e binds to its pre-mRNA and mature mRNA, inhibiting splicing and translation.
• The L30e RNA-binding element features a stem-asymmetric loop-stem structure forming a kink-turn.

Purpose of the Study:

• To investigate the structural basis of L30e autoregulation.
• To identify protein and RNA variants that modulate L30e binding and repression.
• To gain insights into the architecture of the L30e RNA-binding element.

Main Methods:

• A bacterial genetic system was employed to screen for L30e protein variants.
• Reporter mRNAs containing the L30e RNA-binding element were used to assess repression.
• Random mutagenesis of L30e and screening against RNA mutants were performed.

Main Results:

• Specific RNA nucleotide changes were found to affect L30e repression.
• A glycine to serine mutation in L30e restored activity to a specific RNA variant.
• An asparagine to alanine mutation in L30e suppressed an RNA substitution.
• A compensatory RNA mutation was identified within a defective RNA variant.

Conclusions:

• The identified suppressor mutations provide new insights into L30e RNA recognition.
• This study elucidates the architecture of the functional L30e RNA-binding element.
• Understanding these interactions is crucial for RNA-binding protein research.