FIGURE 2.

Z-RNA is a natural ligand of Zα domains. (A) Zα amino acids interacting with a r(CpG)₃ duplex (PDB ID: 2GXB). Underlined residues are mutated in cases of Aicardi Goutières syndrome (Herbert 2019). (B) Cartoon schematic of the key residues of Zα and their interactions with the r(CpG)₃ duplex in the Z-conformation. (C) Sequence alignment between Zα domains from different Zα-containing proteins and species. Only sequences from Zα domains with structures solved in complex with Z-DNA or Z-RNA were used for the alignment. The residue numbering is based off ADAR1 Zα. Consensus sequence: uppercase, 100% conserved; lowercase, one letter with high frequency; +, two letters with high-frequency; −, no consensus.