Читать книгу Snyder and Champness Molecular Genetics of Bacteria - Tina M. Henkin - Страница 55

Because the two strands of DNA are wrapped around each other to form a double helix, the helix has two grooves between the two strands (Figure 1.1). One of these grooves is wider than the other, so it is called the major groove. The other, narrower groove is called the minor groove. Most of the modifications to DNA that are discussed in this and later chapters occur in the major groove of the helix.