- One important principle is that all viral genomes must be copied to produce messenger RNAs (mRNAs) that can be read by host ribosomes.
- A universal function of viral genomes is to specify proteins.
What information is encoded in the viral genome?
Gene products and regulatory signals for:
- Replication of the viral genome
- Assembly and packaging of the genome
- Regulation and timing of the replication cycle
- Modulation of the host defences
- Spread to other cells and hosts
What information is not encoded in the viral genome?
- genes encoding a complete protein synthesis machinery (e.g., no ribosomal RNA and no ribosomal or translation proteins); note: the genomes of some large DNA viruses contain genes for transfer RNAs (tRNAs), aminoacyl-tRNA synthetases, and enzymes that participate in sugar and lipid metabolism
- genes encoding proteins of energy metabolism or membrane biosynthesis telomeres (to maintain genomes) or centromeres (to ensure segregation of genomes)
- Probably we haven’t found them yet