Figure 6.

Principal Component Analysis of TerL^T4 Reveals Lid Subdomain Motion Upon ATP Binding. (A) Principal component analysis (PCA) of TerL^T4 apo simulation shows little concerted motion of the lid subdomain (also called the NII-subdomain in TerL^T4 literature), circled by black dashed circle. Residues are colored based on the magnitude of root-mean-square fluctuations during the simulation, with red representing least mobile residues and blue representing most mobile residues. Arrows represent the projection of the individual residue motions onto the first principal component. (B) Principal component analysis of the first 10 ns of TerL^T4 ATP-bound simulation shows concerted rotation of the lid subdomain towards the ATPase active site consistent with prior experimental studies of Sf6 and P74-26 terminases. (C) Principal component analysis of the last 10 ns of TerL^T4 ATP-bound simulation shows little lid subdomain motion, indicating that the lid subdomain is stable in the closed conformation once the rotation is complete.