Index >> Bacteriophages - Part Two >> Regulation

Regulation - Synthesis of protein and replication by the plus strand are appropriately timed, and do not occur simultaneously: The major translational protein is the coat protein. It is synthesized though out infection. The ratio of the three proteins synthesized is 20 coat protein: 5 replicase subunit:

1 maturation protein. The secondary structure of phage RNA determines this preferential synthesis of/coat protein.

The maturation protein is therefore synthesized only once in the life of the RNA. Replicase gene translation is controlled by HFI, which promotes the binding of ribosomes to this gene.

Translation of the replicase gone is favoured early in infection because the availability of HFI decreases subsequently. The coat protein is formed later in infection.

It represses replicase gene translation because of its ability to bind strongly with its ribosome binding site (translational repression).