The main physical barriers—the body’s first line of defense—are the epithelial layers of the skin and of the mucosal and glandular tissue surfaces connected to the body’s openings

TLS Online TPP Program

#Id: 2906

#Unit 3. Fundamental Processes

Two to four monomers of Dna AA TP bind at the origin, and after release of DiaA, they recruit two "pre-priming" complexes of the DnaB helicase bound to DnaC-ATP, so that there is one DnaB-DnaC-ATP complex for each of the two (bidirectional) replication forks.

TLS Online TPP Program

#Id: 2907

#Unit 3. Fundamental Processes

The function of DnaC is that of a chaperone to repress the helicase activity of DnaB until it is needed.

TLS Online TPP Program

#Id: 2908

#Unit 3. Fundamental Processes

Each DnaB-DnaC complex consists of six DnaC monomers bound to a hexamer of DnaB

TLS Online TPP Program

#Id: 2909

#Unit 3. Fundamental Processes

he prepriming complex generates a protein aggregate of 480 kD, which corresponds to a sphere of radius 6 nm

TLS Online TPP Program

#Id: 2912

#Unit 3. Fundamental Processes

Each DnaB activates a DnaG primase-in one case to initiate the leading strand, and in the other to initiate the first Okazaki fragment of the lagging strand

TLS Online TPP Program

#Id: 2913

#Unit 3. Fundamental Processes

Gyrase, a type II topoisomerase, provides a swivel that allows one DNA strand to rotate around the other.