Fig. 3.

Anchoring of the HRDC domain. (A) The exonuclease–HRDC interaction in Rrp6p. The exonuclease domain is shown as a blue cartoon with the residue 243–249 region as blue sticks, the N-terminal domain as green sticks, D457 as yellow sticks, and the HRDC-domain as a red cartoon. Dashes indicate observable hydrogen bonds. (B) The exonuclease–HRDC interaction in E. coli RNase D. The exonuclease domain is shown as a blue cartoon with the residue 33–39 region as blue sticks, D232 as yellow sticks, and HRDC1 as a red cartoon.