21. 4 A Zinc finger motif is a DNA-binding domain 0● Figure 21. 4 Zinc ● fingers may form OoO a-helices that Forms Forms B-sheeto-hellx insert into the major groove associated withβ sheets on the other side 请莘大Figure 21.4 Zinc fingers may form a-helices that insert into the major groove, associated with b￾sheets on the other side. 21.4 A zinc finger motif is a DNA-binding domain