Question

Which subunit of DNA polymerase III provides processivity? Which protein complex loads this subunit onto the DNA?

A) Clamp loader provides processivity; DNA gyrase loads the subunit.
B) Sliding clamp provides processivity; clamp loader loads the subunit.
C) Primase provides processivity; helicase loads the subunit.
D) DNA ligase provides processivity; sliding clamp loads the subunit.

Answer 1

The sliding clamp subunit of DNA polymerase III provides processivity and is loaded onto the DNA by the clamp loader complex, making option B the correct answer to the student's question.

Step-by-step explanation:

The subunit of DNA polymerase III that provides processivity is the sliding clamp. This subunit enables the DNA polymerase to slide along the DNA template without dissociating after adding each nucleotide. The protein complex responsible for loading this subunit onto the DNA is the clamp loader. Therefore, the correct answer to the question is B) Sliding clamp provides processivity; clamp loader loads the subunit.