Non coding RNAs

Telomerase RNA component (TERC): Plays a role in extending the ends of linear chromosomes during DNA replication in eukaryotes.

X inactive-specific transcript (XIST): Involved in chromatin structure and transcription, specifically in the inactivation of one X chromosome in female eukaryotes.

Hox transcript antisense intergenic RNA (HOTAIR): Regulates chromatin structure and transcription, impacting gene expression in eukaryotes.

RNaseP RNA: Facilitates the processing of tRNA molecules by cleaving their precursors in eukaryotes.

Small nuclear RNA (snRNA): Critical for splicing pre-mRNA by forming part of the spliceosome in eukaryotes.

Small nucleolar RNA (snoRNA): Participates in the processing of rRNA molecules, modifying and guiding chemical changes in eukaryotic ribosomal RNA.

Transfer RNA (tRNA): Functions in translation, bringing amino acids to the ribosome during protein synthesis in both eukaryotes and prokaryotes.

Ribosomal RNA (rRNA): Forms the structural and functional core of ribosomes, enabling translation in eukaryotes and prokaryotes.

Antisense RNA: Regulates translation by binding complementary sequences to block or modify gene expression in eukaryotes.

MicroRNA (miRNA): Involved in translation and RNA degradation, suppressing gene expression post-transcriptionally in eukaryotes; endogenous ncRNA that are 20-25 nts in length

Small interfering RNA (siRNA): plays a role in translation and RNA degradation, exogenous ncRNAs that are 20-25 nts in length and participate in RNAi

RNA component of signal recognition particle (SRP): Essential for protein targeting and secretion, guiding nascent proteins to the endoplasmic reticulum in eukaryotes and prokaryotes.

Viral RNA: Serves as the genome for RNA viruses, carrying genetic information for viral replication.

CRISPR RNA (crRNA): Functions in genome defense in prokaryotes by guiding the CRISPR-associated proteins to target and degrade foreign DNA.

PIWI-interacting RNA (piRNA): Protects the genome in eukaryotes by suppressing transposon activity, contributing to genome defense.

Guide RNAs: Aid in mRNA modification, ensuring proper editing and functionality of transcripts in eukaryotes.

non-coding RNAs

• RNA molecules that do not encode polypeptides

ribozymes

• RNA molecules with catalytic functions

long non-coding RNAs

• RNA molecules that are longer than 200 nucleotides

small regulatory RNAs

• RNA molecules that are shorter than 200 nucleotides

RNA interference (RNAi)

• a process in which double stranded RNA causes the silencing of mRNA

RNA-induced silencing complex (RISC)

• complex that mediates RNAi

small recognition particle (SRP)

• a complex between ncRNAand one or more proteins that directs newly synthesized polypeptidesto the ER in eukaryotes or plasma membrane in prokaryotes