Supplementary Figure 5: MurJTA is strikingly different from canonical MATE transporters, especially in TMs 1, 2, and 8, as well as in cavity electrostatics.
From: Crystal structure of the MOP flippase MurJ in an inward-facing conformation
(a) Structural alignment between MurJTA (colored) with MATE transporters (gray) performed for individual lobes split at the start of TM7, with TMs 13 and 14 removed. Structural differences are especially pronounced at TMs 1 and 2, while TM8 of MurJTA contains a segment that deviates from the α-helical geometry observed in MATE structures. The divergence at TM7 is likely a result of the inward-facing conformation of MurJTA as compared to the outward-facing conformations of the MATE transporters. Structures of MurJTA (PDB ID:5T77), PfMATE (3VVN), NorM-VC (3MKT), NorM-NG (4HUK), DinF-BH (4LZ6), and ClbM-EC (4Z3N) were used for the alignment. (b) Surface charge differences between MurJTA and other MATE transporters. Surface electrostatics for MurJTA (PDB ID: 5T77) and MATE transporters NorM-VC (3MKT), NorM-NG (4HUK), PfMATE (3VVN), DinF-BH (4LZ6), and ClbM-EC (4Z3N) were calculated by the APBS plugin in PyMOL. The cavities of MurJTA and PfMATE are primarily cationic, in contrast to the strongly anionic cavities of NorM-VC, NorM-NG and ClbM-EC. The cavity of DinF-BH appears to have both weakly cationic and anionic patches.
