Fig. 8. Model of the sequence specificity of Zα.

Cartoon model depicting the proposed sequence specificity of Zα. A Z-RNA-prone region of dsRNA is flanked by regions of less stable A-form RNA (left). First, Zα dynamically interacts with the Z-prone sequence (usually comprising YpR steps and non-Watson–Crick pairs) in the initial contact conformation, which begins to convert the region to the Z-conformation, while also destabilizing the neighboring A-form regions (middle). This promotes the binding of another Zα molecule which then stabilizes the Z-conformation and converts the RNA into an A-Z junction (right), which may contain flipped out base pairs as has been seen for B-Z junctions³⁴.