2
$\begingroup$

So I'm reading about how mutations in DNA can be caused by oxidative damage. An example of a product of oxidative damage is given: 8-oxo-7-hydrodeoxyguanosine

My textbook says that this product frequently mispairs with A, resulting in a high level of G-->T transversions.

What I'm not understanding is why it's a G-->T transversion. If the 8-oxo-G is pairing with A, resulting an an A-G pair, isn't this a T-->G transversion? Or does the order not matter?

$\endgroup$
1
$\begingroup$

Originally the position had a G:C pair. After the mutation, there is an oxoG:C pair. Upon replication, the strand with C will pair to G and the original pair will be created as expected. However, since oxoG can also pair with A, the strand with oxoG may form an oxoG:A pair. Another round of replication gives the products T:A and oxoG:A. Thus the G in the original strand is replaced by T (ie it is a G$\ce{->}$T transversion).

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.