DYW domain

The DYW domain, which was named by the highly conserved last three amino acids, aspartate, tyrosine, and tryptophan, has been proposed as the best candidate to elicit deamination employing a HxE(x)nCxxC zinc ion binding signature.

We describe the first structures of a plant organellar RNA editosomal DYW domain in an autoinhibited and activated state. In addition to a typical cytidine deaminase fold, DYW domains contain a characteristic DYW motif, stabilized by a Zn atom, as well as a unique gating domain (Fig. 1), which controls Zn-mediated catalysis sterically and catalytically.

The catalytic regulation of DYW domain showed a novel protein regulation principle where upon activation a major movement of the gating domain alters the coordination around the catalytic Zn-atom whereas in the inactive state, the Zn is inhibited by its coordination setting (Fig. 2).

Our results revealed key mechanisms in plant organellar RNA editing catalysis, its autoinhibition and have far-reaching implications for mitochondrial and chloroplast homeostasis.

Takenaka, M., Takenaka, S., Barthel, T., Frink, B., Haag, S., Verbitskiy, D., Oldenkott, B., Schallenberg-Rüdinger, M., Feiler, C.G., Weiss, M.S., Palm, G.J., Weber, G. (2021) DYW domain structures imply an unusual regulation principle in plant organellar RNA editing catalysis. Nature Catalysis 4, 510–522. https://doi.org/10.1038/s41929-021-00633-x