Question

Congratulations, you've discovered a new region of DNA on the E. coli chromosome! The region is transcribed but there are no ribosomal binding sites or stop codons. Deletion of this region increases mutation rates for E. coli. Describe a potential mechanism that explains these sequence and phenotypic observations.

Answer 1

A ribosome binding site is a sequence of nucleotides upstream of the start codon of an mRNA transcript that is responsible for the recruitment of a ribosome during the initiation of protein translation. If this sequence is absent that means ribosome will not be recruited to the right place and there will be no translation. The absence of stop codons indicates that if there is translation occurring, it will continue non -stop. This means that sequences are actually transcribed and not translated and as the question says that deletion of this region increases mutation rates that do mean that it is certainly a quite important region which could be integral to gene expression regulation.

Thus these regions code for certain RNAs which are important for control of gene expression in other regions. In the absence of these regions, gene control is affected hence rate of mutations increases in the absence of this critical region.