Types, size and function of RNA
Protein coding or non-coding | Type of RNA | Size (number of nucleotides) | Function |
Coding | Messenger RNA (3%–5% of total)19 | Variable | Translated into proteins by ribosomes. |
Non-coding structural and catalytic | Ribosomal RNA (80% of total)19 | Four subunits (120, 160, 1900 and 4700 nucleotides) | Facilitates mRNA translation into protein. |
Transfer RNA19 | 80 | Collects amino acids and delivers to ribosome to make protein. | |
Non-coding | Small nuclear and small nucleolar RNA (snRNA/snoRNA)20 | 60–300 | Control mRNA and rRNA splicing. |
Regulatory non coding | MicroRNA (miRNA)12 | 19–24 | Regulate gene expression at a post-transcription level by translational repression or mRNA degradation. |
Piwi-interacting RNA19 | >23 | Gene silencing of transposons and repetitive sequences. | |
Long non-coding RNAs12 | >200 | Many and broad functions including: gene regulation, chromosomal dynamics and telomere biology. |