Figure 3.
Modular recognition of DNA sequence.A, zif268 has three zinc fingers (each colored differently) that bind DNA (1ZAA). Each zinc is coordinated by two His and two Cys side chains (sticks). Each finger contacts bases in the major groove with two side chains. B, TAL effector protein (3UGM). Alternate 34 amino acid TAL repeats are colored red and blue.