Small interfering RNA, or as also called, short interfering
RNA/silencing RNA (siRNA), belongs to a group of double-stranded
RNA non-coding RNA molecules.
It is like miRNA and is a part of the RNA interference (RNAi)
pathway.
It intervens with specific genes expression containing
complementary sequence of nucleotide through mRNA degredation post
transcription.
By degrading mRNA it inhibits the translation of proteins.
Structure of siRNA is well defined containing a short double
stranded RNA having phosphorylated 5' ends and a 3' hydroxlated
end.
The RISC protein function to initially
activates the siRNA and activity of siRNA in RNAi is dependent
largely on the binding efficiency of the siRNA to RNA-induced
silencing complex (RISC).
Duplex siRNA binding to RISC results in unwinding and cleavage
of sense strands by endonucleases.