Ligation of Okazaki fragments during lagging strand DNA synthesis

Extension of DNA synthesis stops when the 5' end of the RNA primer is encountered. The exonuclease acitivty of the DNAPol III removes the primer, DNAPo lI fills in the gap, and DNA ligase joins the 3' and 5' ends.

Figure © 2012 TA Brown, Introduction to Genetics (1st ed.); additional text © 2014 by Steven M. Carr