RT Journal Article
SR Electronic
T1 Thermodynamic analysis of Zα domain-nucleic acid interactions
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2022.01.17.476573
DO 10.1101/2022.01.17.476573
A1 Bharath Srinivasan
A1 Krzysztof Kuś
A1 Alekos Athanasiadis
YR 2022
UL http://biorxiv.org/content/early/2022/01/17/2022.01.17.476573.abstract
AB DNA/RNA molecules adopting the left-handed conformation (Z-form) have been attributed with immunogenic properties. However, their biological role and importance has been a topic of debate for many years. The discovery of Z-DNA/RNA binding domains (Zα domains) in varied proteins that are involved in the innate immune response, such as the interferon inducible form of the RNA editing enzyme ADAR1 (p150), Z-DNA binding protein 1 (ZBP1), the fish kinase PKZ and the poxvirus inhibitor of interferon response E3L, indicates important roles of Z-DNA/RNA in immunity and self/non-self-discrimination. Such Zα domain-containing proteins recognise left-handed Z-DNA/RNA in a conformation-specific manner. Recent studies have implicated these domains in virus recognition. Given these important emerging roles for the Zα domains, it is pivotal to understand the mechanism of recognition of the Z-DNA/Z-RNA by these domains. To this end, we assessed the binding thermodynamics of Zα domain from ORF112 and ADAR1 on T(CG)3 and T(CG)6 oligonucleotides which have high propensity to adopt the Z-conformation. Our study highlights important differences in the mode of binding by the two Zα domains originating from different proteins. Site-directed mutagenesis was employed together with isothermal titration calorimetry to tease apart finer details of the binding thermodynamics. Our work advances the understanding on binding thermodynamics of Zα domains to their cognate nucleic acid substrates and contributes to the efforts to gain a complete appreciation of this process.Competing Interest StatementThe authors have declared no competing interest.ITCIsothermal titration calorimetryADAR1Adenosine deaminase acting on RNA 1ZBP1Z-DNA binding protein 1MWC modelMonod-Wyman-Changeux modelKNF modelKoshland-Nemethy-Filmer model