biology help 5 Which subunit of eukaryotic RNA polymerase is

biology help

5. Which subunit of eukaryotic RNA polymerase is orthologous to the beta subunit of prokaryotic RNA polymerase? 6. Which fure characteristic dothe beta subunit of prokaryotic RNA polymerase and the answer to #5 share?

Solution

5) The DNA polymerase delta , which is a multi subunit enzyme, that results in extension of primers. This enzyme is associated with a proliferating cell nuclear antigen, PCNA . This enzyme is found largely in the nuclei of proliferating cells. This enzyme in its 3D structure is highly similar to the Beta subunit of the prokaryotic DNA polymerase III. This enzyme has a function analogous to that of the Beta subunit , although, there has not been primary sequence homology observed. This enzyme forms a circular clamp similar to the Beta clamp structure and enhances the processivity of the polymerase by several folds.

6) The DNA polymerase delta has a 3\'--->5\' proofreading exonuclease activity , and carries out both leading and lagging strand synthesis , which is similar to the dimeric DNA polymerase III.