Читать книгу Cell Biology - Stephen R. Bolsover - Страница 92

DnaB is a helicase. It moves along a DNA strand, breaking hydrogen bonds, and in the process unwinds the helix (Figure 4.1). Two molecules of DnaB are needed, one for each strand of DNA. One DnaB attaches to one of the template strands and moves in the 5′ to 3′ direction; the second DnaB attaches to the other strand and moves in the 3′ to 5′ direction. The unwinding of the DNA double helix by DnaB is an ATP‐dependent process. DnaB is escorted to the DNA strands by another protein, DnaC. However, having delivered DnaB to its destination, DnaC plays no further role in replication.