What can we conclude about a mutational event that renders is1 unable to transpose?

It can be concluded that the mutation is located in one of the inverted repeat sequences at the ends of the element

Explanation:

IS stands for insertion sequence. It is basically a short stretch of DNA that has the ability to transpose and it is an example of a simple transposable element. IS1 is an example of an insertion sequence transposon. The structure of this transposon basically consists of a coding region which is flanked on either side by the inverted repeats. The inverted repeats flanking the transposon are essential for the transposase enzyme to perform its function as the enzyme recognizes these repeats and thus, it knows where to cut the transposon and then its transposition can occur. If a mutational event occurs that makes IS1 incapable of transposing then it can be concluded that there is a mutation in one of the inverted repeat sequences.