  Our data challenge Chen et al.'s interpretation of smFRET results, i.e. the
repetitive unfolding of G4 with one-base translocations. We believe that the
observed oscillatory curve represents the alternate binding of DHX36 to the 3'
and 5'G-tetrad of G4s, rather than the repetitive unfolding between the
canonical and the transformed non-canonical G4s. Noteworthily, our results
reported here also call into question the previously published smFRET data of
helicase-mediated G4 unfolding. Therefore,discriminating the smFRET signal of
repetitive binding from that of unfolding is very important to avoid
misinterpreting smFRET results.
