IMG00207

Mjjjgcułar model for attenuatlon (cont,):

pggition of tkejlfeosome ptavs an łmoortant role in attenuatlon: When Trp is abundant (and not required):

1.    Ribosome does not stall at the codons and contlnues translating the leader polypcptide, ending In reglon2.

2.    Region 2 cannot pair with region 3, instead region 3 pairs with region 4.

3.    Pairing of region 3 and 4 is the "attenuator" sequcnce and acts as a terminatłon signal.

4.    Transcription terminates before the trp synthesizlng genes are reached.