Fig. 5: Interaction of the gp61 primase with the active and closed-ring gp41 helicase.
From: Structural basis of the T4 bacteriophage primosome assembly and primer synthesis
a A detailed architecture of the gp61 primase indicating the NTL: N-terminal lobe of the RPD and the TOPRIM, a signature domain conserved in all primases. b A tilted bottom view of the T4 primosome showing the gp61 primase in cartoon binding to the NTDs of the gp41 helicase in surface. The binding mode is essentially the same in all three gp61 binding poses. The gp61 domains are colored as in (a). Enlarged views showing the detailed interactions between gp41 NTDs and (c) the HIM1 and (d) the HIM2 of the gp61 primase. The interacting residue pairs are connected by dashed black lines. Enlarged views showing detailed interactions between ssDNA and (e) the zinc-ribbon core and (f) the NTL in the RPD of the gp61 primase. Created with BioRender.com.
