What is Polycistronic in biology?
polycistronic Describing a type of messenger RNA that can encode more than one polypeptide separately within the same RNA molecule. Bacterial messenger RNA is generally polycistronic. Compare monocistronic. A Dictionary of Biology.
What is Polycistronic organization?
In prokaryotes, however, gene organization is polycistronic: a specific group of enzymes or proteins needed for a metabolic pathway, for example, is transcribed in tandem by a sequence of multiple cistrons (independent units of genetic information).
Are Polycistronic mRNA rare?
Which of the following is NOT a feature of eukaryotic gene expression?…Correct!
| A. | polycistronic mRNAs are very rare |
|---|---|
| D. | mRNA is often extensively modified before translation |
| E. | multiple copies of nuclear genes, and pseudogenes can occur |
Are Polycistronic mRNAs in eukaryotes?
A corollary of the scanning model is that eukaryotes should normally have no polycistronic gene structures, i.e. mRNAs that code for more than one protein product. However, polycistronic mRNAs are known to exist in eukaryotic viruses [5], hence the eukaryotic translational machinery must have ways to deal with them.
Is lac operon Polycistronic?
Bacterial operons are polycistronic transcripts that are able to produce multiple proteins from one mRNA transcript. In this case, when lactose is required as a sugar source for the bacterium, the three genes of the lac operon can be expressed and their subsequent proteins translated: lacZ, lacY, and lacA.
Are humans Polycistronic?
Among the few examples of human polycistronic genes recognized, the additional cistrons appear to allow for 1) co-expression of multiple subunits of a protein that is part of a complex; 2) co-expression of similarly functioning proteins under slightly different spatial or temporal patterns, 3) or co-production of novel …
Is Procaryotes a Polycistronic mRNA?
Polycistronic mRNAs are common in prokaryotes. For example, the lac operon (q.v.) of E. coli generates a polycistronic mRNA. Contrast with monocistronic mRNA.
Is an exon bigger than a gene?
The total number of exons for the gene may be larger than shown. Many proteins are encoded by genes with a single exon or have multiple exons but no introns in their protein-coding regions.