Structure of the Arabidopsis thaliana DCL4 DUF283 domain reveals a noncanonical double-stranded RNA-binding fold for protein–protein interaction

DCL4 DUF283 is a zinc-binding module. (A) ITC titration of DCL4 DUF283 by zinc chloride. (B) Chemical shift perturbation after addition of zinc chloride to a ¹⁵N-labeled DCL4 DUF283. The chemical shifts are monitored by ¹H–¹⁵N heteronuclear single quantum correlation (HSQC) spectra. The spectrum of the free protein is shown in blue and the spectrum after addition of a fivefold molar excess of zinc chloride is shown in red. (C) Ribbon representation of the DCL4 DUF283 domain colored according to chemical shift perturbation induced following the addition of zinc chloride. Residues that are affected/not affected by the zinc addition are shown in red/cyan. (D) Surface representation of the DCL4 DUF283 domain colored according to chemical shift perturbation induced following the addition of zinc chloride. The same orientation as in C.