Movement of the RecG Motor Domain upon DNA Binding Is Required for Efficient Fork Reversal

摘要: RecG catalyzes reversal of stalled replication forks in response to stress bacteria. The protein contains a fork recognition (“wedge”) domain that binds branched DNA and superfamily II (SF2) ATPase motor drives translocation on double-stranded (ds)DNA. mechanism by which the wedge domains collaborate catalyze analogous eukaryotic remodelers is unknown. Here, we used electron paramagnetic resonance (EPR) spectroscopy probe conformational changes between binding Thermotoga maritima RecG. Upon DNA, ATPase-C lobe moves away from both ATPase-N domains. This change consistent with model fully engaged substrate constructed crystal structure bound junction together recent cryo-electron microscopy (EM) structures chromatin complex dsDNA. We show mutational analysis conserved loop within (TRG) motif was unstructured essential for DNA-dependent changes. Together, this work helps provide more coherent remodeling related enzymes.