Question

The pol III beta subunit is a ring-shaped clamp that embraces DNA in a central 35 Å hole, tethering the remainder of pol III to the template.

Which of the following accurately describes the structure of the DNA polymerase III beta subunit sliding clamp protein?

PDB ID: 2POL

The pol III beta subunit is a ring-shaped clamp that embraces DNA in a central 35 Å hole, tethering the remainder of pol III to the template.

Which of the following accurately describes the structure of the DNA polymerase III beta subunit sliding clamp protein?

It's a monomer.

It's a homodimer with monomers arranged head to head and tail to tail (N--C-->C--N-->).

It's a homodimer with monomers arranged head to tail (N--C-->N--C-->).

It's a heterodimer with monomers arranged head to head and tail to tail (N--C-->C--N-->).

It's a heterodimer with monomers arranged head to tail (N--C-->N--C-->).

Answer 1

The answer is - It's a homodimer with monomers arranged head to tail (N--C-->N--C-->).

The beta clamp subunit of DNA polymerase III is a homodimer with monomers arranged head to tail (N--C-->N--C-->). That is the N terminus interacts with the C terminus.