Figure 7
Comparison of GatD/MurT with Mur ligases and putative conformational changes upon ligand engagement. (a) Structural alignment of GatD/MurT (left) and S. aureus MurE32 and A. baumannii MurF33 structures (right) was performed based on the Mur ligase middle domain (light green). The C-terminal domain (cyan) is rotated toward the middle domain in the MurE and MurF structures. A UDP-binding N-terminal domain (orange) is present in MurE and MurF but not in MurT. (b) Putative model of an active conformation of GatD/MurT with the domain movement modeled after the S. aureus MurE structure. The GatD catalytic triad and the bound AMPPNP molecule are shown as colored sticks, the relevant muramyltripeptide portion of the superimposed substrate of MurE (MurNAc-L-Ala-γ-D-Glu-L-Lys, but lacking UDP) is shown in grey stick representation for reference. The DNAAD motif, suggested to be involved in substrate binding is highlighted in salmon (right).
