to be A1, as it is more abundant within the virion and is also required for infection. However, once the sequence of Qβ was determined, A1 was revealed to be a readthrough of the leaky stop codon. A2 is the maturation protein for Qβ and has an additional role of being the lysis protein. The mechanism of lysis is similar to that of penicillin; A2 inhibits the formation of peptidoglycan by binding to MurA, which catalyzes the first enzymatically committed step in cell wall biosynthesis. Experiments RNA from Bacteriophage Qβ was used by Sol Spiegelman in experiments that favored faster replication, and thus shorter strands of RNA. He ended up with Spiegelman's Monster, a minimal RNA chain of only 218 nucleotides that can be replicated by Qβ replicase. References External links Bacteriophages Fiersviridae