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Figure 5.
Figure 5. Schematic representation of the proposed
nucleotide-dependent relocation of L1 and L2 in EBP mediated
through the atomic switch. For simplicity, we focus on the
atomic switch and L1 and L2 loops within one subunit of the EBP
hexamer. The GAFTGA motif is locked into an unfavourable
conformation for s54 interaction in the ADP bound state as
represented by ADP and ADP-NtrC1 structures (right). At the
initial stage of hydrolysis as represented by ATP-PspF[1-275]
structure, E108 stably interacts with N64, causing relocations
of linker 1 and central b-sheet, affecting the network of
interactions which coordinate GAFTGA containing L1 loop,
ultimately releasing L1 loop for s54 interaction (left and
bottom). At the point of ATP hydrolysis, the GAFTGA motif
engages with s54 and L1 and L2 loops are stablized (top). Upon
Pi release, the interaction between N64 and E108 breaks,
allowing the GAFTGA motif to collapse and return to the ADP
bound state (right).
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