And so the Aug actually codes for this methionine molecule. And the formal methionine looks like this. The formal simply means we have this group attached onto the central carbon as shown in the following diagram. So once that molecule, the rRNA, binds onto the Shine Del Garner sequence, it forms that complex, it stimulates the tRNA to bring this form of methionine onto that Aug and that essentially establishes the reading frame of that mRNA molecule. Now, what do we mean by the reading frame or establishing the reading frame? Well, what that means is we essentially establish all the codon sequences that we're going to read on that mRNA molecule.