5S rRNA is a tiny, 120-nucleotide RNA held in the ribosome’s large 60S subunit by its partner protein, RPL5. To keep up with massive cellular demand, RNA Polymerase III transcribes 5S rRNA from a massive tandem gene array on chromosome 1. The gene is repeated tens to hundreds of times head-to-tail. Each 2,168 bp repeat unit contains the 120 bp gene alongside a non-transcribed spacer (Alu, promoter, terminator, and microsatellites). Hundreds of copies are kept near-identical through gene conversion—transferring sequence data between neighboring repeats to preserve sequence fidelity.
What the new interactive atlas reveals:
- Haplotypes: Per-array maps showing copy number, variants, and gene-conversion stripes.
- Variants: Detailed tracking of variant frequency, function, and disease associations.
- Function: Folded rRNA structures mapped by deep mutational scanning to show effect of single-nucleotide substitutions on 60S incorporation and RNA expression.
- A fascinating look at how genome architecture balances high-volume production with strict sequence control!