Team:Hong Kong HKUST/riboregulator/regulatory RNAs catalog

Riboregulators regulate translation by having two elements, a cis-repressive sequence upstream of RBS in mRNA, and a non-coding RNA device, called trans-activating RNA. The cis-repressive sequence will binds to the 5'UTR, including the RBS by Watson-Crick base pairing, the sequestration of RBS represses translation. While trans-activating RNA will form complementary bases to cis-repressive sequence and exposing RBS for ribosomal binding and allow translation.

Proposed Categories: /RNA/non_coding/post_transcriptional/Riboregulator

A riboswitch is a segment on mRNA that have the ability to detect small molecules or temperature, and regulate gene expression in on or off manner. Riboswitches usually contain a region for binding of small molecules, as known as sensor domain, and a region for gene regulation, as known as regulatory domain.In the presence of suitable ligand in the sensor domain, the structure of riboswitch will change. This change in conformation of riboswitch may give various action including translation inhibition or mRNA degradation.

RNA-OUT is a small non-coding RNA that works at RNA level . RNA-OUT will bind to 5'UTR, which include RBS, of mRNA and prevents ribosome from binding to mRNA to inhibit translation of downstream gene. RNA-IN is also a non-coding RNA that is antisense to RNA-OUT and the binding of RNA-IN and RNA-OUT will prevent RNA-OUT from binding to mRNA, thus allowing ribosome to bind to mRNA and initiate translation.

siRNAs usually involved in RNA interference pathway. siRNA s are produced by "dicing" long double stranded RNA into 21-nucleotides small fragments. The siRNAs will then bind to a protein and one strand of siRNA is removed. Then siRNA, which have complementary base pairs with its target mRNA, will binds to target mRNA. The binding of siRNA usually causes the degradation of target mRNA, result in inhibition of gene expression.

sgRNAs are non-coding RNA that have a hairpin structure mimicking trans-acting RNA and crRNA in CRISPR system. When in complex with Cas9 the,complex are able to target specific DNA sequence and breaking double stranded DNA.