Replication is unidirectional when a single replication fork is created at an origin.

TLS Online TPP Program

#Id: 3026

#Unit 3. Fundamental Processes

Priming activity is required to provide 3'-0H ends to start off the DNA chains on both the leading and lagging strands.

TLS Online TPP Program

#Id: 3027

#Unit 3. Fundamental Processes

Each Okazaki fragment starts with a primer sequence of RNA - 10 bases long that provides the 3'-0H end for extension by DNA polymerase.

TLS Online TPP Program

#Id: 3028

#Unit 3. Fundamental Processes

Primers start with the sequence pppAG positioned opposite the sequence 3 '-GTC-5' in the template.

TLS Online TPP Program

#Id: 3029

#Unit 3. Fundamental Processes

The oriCsystem, named for the bacterial origin, basically involves the association of the DnaG primase with the protein complex at the replication fork.

TLS Online TPP Program

#Id: 3030

#Unit 3. Fundamental Processes

The use of a single type of catalytic subunit, however, may be atypical. In the bacterium Bacillus subtilis, there are two different catalytic subunits.

PolC is the homolog to E. coli's DnaE, and is responsible for synthesizing the leading strand.

A related protein, DnaE8 s. is the catalytic subunit that synthesizes the lagging strand.

TLS Online TPP Program

#Id: 3031

#Unit 3. Fundamental Processes

The DNA Pol III holoenzyme has at least two catalytic cores. a processivity clamp, and a dimerization damp-loader complex.