transcription and translation questions - when do they start and stop in bacteria? (Oct/27/2010 )
Sorry if this sounds silly but my fundamentals in molecular biology are not particularly strong.
As far as I understand, transcription starts when the RNA polymerase binds to the promoter, thereby generating the mRNA. But when and does transcription stop? Is there some consensus sequence to signal termination?
If I understand correctly, after the mRNA has been generated, ribosomes bind to the ribosome binding site which has the consensus sequence AGGAGG. Then it searches for the start codon ATG and starts translating until it reaches a stop codon. What happens next? Does it fall off immediately or does it continue searching down the mRNA until some sequence/region is reached to signal dissociation? Also, since there are many sequences similar to AGGAGG wouldn't the ribosome be producing lots of non-specific proteins?