Figure 5
Putative mode of nucleic acid binding.
(A) A detail of the Zn knuckle-RNA interactions of mouse Lin28 with let-7 microRNA21 (PDB code: 3TRZ), showing the critical role of aromatic residues stacking with the nucleic acid basis. (B) The Xenopus Zn knuckle is shown in the same orientation; for the sake of clarity, secondary structure elements are not depicted. The two conserved hydrophobic residues Phe616 and Trp624 are shown as ball-and-stick.
