Figure 5.

AimB and MreB interact directly. (A) The location of the 26 residues of MreB that were mutated to the amber codon for in vitro cross-linking assays are highlighted in blue on the CcMreB crystal structure. Arginine 185 is highlighted in red. (B) In vitro cross-linking experiments were performed by incorporating the UV cross-linkable non-natural amino acid pBPA at various positions in MreB (Materials and Methods). Cross-linked samples were analyzed by immunoblotting for MreB. A cross-linked band was observed for position R185 (blue rectangle). (C) UV cross-linking of R185 was performed as in (A) using a FLAG-tagged AimB construct. Immunoblotting for MreB or the FLAG-tagged AimB showed similar cross-linked bands. (D) R185 is at the base of the cleft where AimB and MreB are predicted to interact. The intermolecular distance between MreB^R185 and AimB^G64, the nearest AimB residue, was quantified over the course of our CcMreB-AimB and EcMreB-AimB MD simulations. AimB interacts with CcMreB more stably compared with EcMreB, as shown by a smaller distance between the two residues. To see this figure in color, go online.