Full-Range Profiling of tRNA Modifications Using LC-MS/MS at Single-Base Resolution through a Site-Specific Cleavage...

Area of Science:

• Biochemistry
• Molecular Biology
• Genomics

Background:

• Transfer RNAs (tRNAs) are extensively modified, impacting their function.
• Current methods like LC-MS/MS for tRNA modification analysis face limitations due to base composition, causing information loss.
• Characterizing tRNA modifications is crucial for understanding cellular processes.

Purpose of the Study:

• To develop a novel method for comprehensive tRNA modification profiling at single-base resolution.
• To overcome limitations of existing techniques in analyzing tRNA modifications.
• To enable accurate de novo sequencing of post-transcriptionally modified tRNAs.

Main Methods:

• Integration of site-specific RNase H digestion with LC-MS/MS and RNA-seq.
• Optimization of digestion products for length and ionization properties.
• Utilizing a linear correlation between collision energies and oligonucleotide m/z for improved CID spectra.
• Application of novel inclusion criteria to eliminate false positives.

Main Results:

• Successful full-range profiling of tRNA modifications with single-base resolution.
• Enhanced information content in collision-induced dissociation (CID) spectra.
• Reduction of false positive modification identifications by up to 95%.
• Complete characterization of five modification species on mouse mitochondrial tRNAHis(GUG) and tRNAVal(UAC).

Conclusions:

• The developed method provides a universally applicable approach for tRNA modification analysis.
• Enables high-sequence coverage de novo sequencing of modified tRNAs.
• Opens new avenues for investigating previously uncharacterized tRNA modifications.