Polycistronic mRNA molecule carries the coding region for several proteins and thus, is transcribed from more than one genes. These proteins function together in a biological process. They are present in bacteria.
- A polycistronic mRNA has ribosome binding site near the start site for each of cistrons.
- Translation initiation can begin at any of these multiple internal sites, producing multiple proteins.
*The presence of polycistronic mRNA has been confirmed in RNA viruses also.
[Monocistronic mRNA molecule encodes a single protein and thus, is transcribed from one gene. It is present in eukaryotes.
Eukaryotic mRNAs have single initiation and termination sites and a single type of polypeptide is produced.
Although polycistronic mRNA is characteristic of prokaryotes but they are present in Trypanosome and nematode and in few insects (eukaryotes) also.]