Structural comparison of new vOTU structures.

(A) Secondary structure overlay of the vOTUs from CCHFV, DGKV, QYBV, and TAGV. The red circles highlight areas of the binding interface that show large structural divergence. The region of the active site is denoted by a black box, with a closeup shown. The relative activities of the DGKV vOTU WT and E152D mutant for Ub-AMC and the peptide Z-RLRGG-AMC are shown, with error bars representing the standard deviation of two independent experiments. (B-C) Specific molecular interactions accounting for structural differences can be identified in distinct regions of the vOTUs. CCHFV vOTU is colored gray, DGKV vOTU in teal, QYBV vOTU in orange, and TAGV vOTU in magenta. Black dashed lines denote atom pairs that are within hydrogen bonding distance.