Many of the gene products involved in DNA synthesis were initially defined by studying mutant E. coli strains that could not synthesize DNA. The dnaE gene encodes the α subunit of DNA polymerase III. What effect is expected from a mutation in this gene? How could the mutant strain be maintained?

Video transcript

Hello everyone and welcome to today's video. So today we have that D N. A polymerase three is going to be profiting and correcting DNA replication errors through Exxon nuclear activity. DNA polymerase three consists of three sub units which are the following gene encodes the alpha subunit. So just like the question states, I want you to recall that D N. A preliminary three is going to be made up by three main sub units which are going to be the alpha, which is the one that we're looking for. Then we have the epsilon and the data sub unit. And just in case you forgot the specific genes that encode for these three, we can refer to the stable in order to figure this out. Remember that we're looking at DNA polymerase three which is here we have that the three genes are going to be encoding depending on the sub unit, D N A E. Here, D N A Q and whole E. These are the three genes that are going to be encoding the three sub units of this D N. A polymerase three. Now this data sub unit is going to be encoded by the whole E jean because of this. We're going to cancel out whole E. Which is answer choice A. Then this epsilon sub unit is going to be encoded by DNA que. We're going to be canceling out D N A Q. Because it is going to be encoding for epsilon and not the alpha subunit. So the only one left really is this D N A E and D N A. Is the gene that is going to be encoding for this off a sub unit. Because of this, we're going to be selecting answer choice c d n a e jean as a correct answer to our question. I really hope this video helped you, and I hope to see you on the next video.