Step I a quick question about DNA polymerase

[purplelife]

Is this true?

"I know that Pol I has both 5' to 3' and 3' to 5' exonuclease activity whereas Pol III has only 3' to 5' exonuclease activity."


Doesn't Pol 1 excises 5 to 3 and proof reads 3 to 5? Does it excises both ways?

Thank you!

 

[CaptainSSO]

I doubt that would ever be a question, but it excises both ways. Otherwise the proof reading would be worthless--the excision is part of the proof reading.

http://en.m.wikipedia.org/wiki/DNA_polymerase_I