Signal recognition particle RNA
The 7SL RNA, and 7S RNA is transcribed in a mammal by RNA polymerase III, usually double-stranded ribonucleic acid ( RNA) that is not translated. RNA is 300 nucleotides long and has a sedimentation coefficient of 7S. It is the backbone of the signal recognition particle ( SRP, signal recognition particle ), which is composed of the RNA and six proteins. SRP is important for the co-translational transport of proteins and directs the ribosome to the endoplasmic reticulum membrane.
It is assumed that the Alu family, a gene family of SINEs, has emerged from a duplicate of a 7SL RNA gene.
In yeast, the RNA is longer ( 11S ), in Escherichia coli is the sedimentation coefficient of 4.5 S and the RNA has a length of 114 nucleotides.