Fig. 3: Molecular details of the interaction between the Z and L proteins.

a Surface diagram of the L–Z complex with the domains indicated and colored as in Fig. 1a. Inset zoom, the Z protein is represented as ribbon with the two binding sites outlined with black boxes and shown in (b). b Detailed views of the two interfaces between the Z and L proteins. Left, loop 1 of Z interaction with palm and core lob of the L protein; Right, loop 2 interaction with core lob and thumb ring. The backbones of L and Z are in ribbons representation. Side chains and main chains involved in interactions are shown as sticks and labeled. Oxygen, nitrogen and sulfur atoms shown in red, blue and yellow, respectively, and salt bridges and hydrogen bonds are indicated as black dashed lines. c Cartoon model of the L protein showing putative tunnels of the template RNA entrance (blue line) and exit (blue dashed line), the product exit (red line) and NTP entrance (black dashed arrow). The catalytic site is indicated by a red asterisk and the CTD is is represented by a gray oval. d Surface representation of L inhibited by Z binding. The RdRP and PB2-N-like domain are partially showed as cut-out view to better display the product RNA exit. The RING domain of Z is colored bright orange, and the modeled N-terminus of MACV Z using LASV Z (PDB 5I72) as template is colored dark orange. The hidden product exit tunnel is showed as red dashed line.