Question

PhiX174 priming reaction

DnaB protein: provides motive force that propels the replication fork.
1. DnaB: helicase moves 5'-3'; 330 kDa hexamer. DnaB is loaded by the ____ proteins (A, B, C). Activates ____ (DnaG).
2. DnaC: acts with DnaB (6 monomers); 29 kDa.
*ATP is used during loading
DnaG: RNA primer synthesis; 60 kDa. DnaG is a special RNA polymerase used only in DNA replication. Activated by ____.

Answer 1

In the phiX174 priming reaction for DNA replication, the DnaB protein is a helicase that unwinds DNA, is loaded by specific proteins, and activates DnaG primase for RNA primer synthesis.

Step-by-step explanation:

The phiX174 priming reaction for DNA replication involves several key proteins, one of which is the DnaB helicase. It moves in the 5'-3' direction and is a 330 kDa hexamer. DnaB is loaded onto the DNA by the tau, delta, and delta prime proteins. This helicase is responsible for unwinding the DNA at the replication fork and is activated by the DnaC protein, acting with DnaB as six monomers and with a size of 29 kDa. ATP is essential during this loading process. DnaB also activates DnaG primase, a 60 kDa enzyme that synthesizes the RNA primer, which is crucial for DNA polymerase to start DNA synthesis. DnaG is a special RNA polymerase used only in DNA replication and is activated by the action of DnaB.