Adenylation domains by themselves have been historically limited to X-ray crystallography due to their size (~50 kDa), which makes them too big for solution-phase nuclear magnetic resonance (NMR) spectroscopy and too small for current cryo-electron microscopy (cryo-EM) techniques. However, with the recent growing interest in studying domain-domain interactions and conformational flexibility of intact NRPS modules, cryo-EM has become an essential technique. Despite the majority of structures being generated through X-ray crystallographic studies, the field as a whole seems to be moving towards understanding the complicated dynamics of NRPS megasynthetases. It should be noted that studies on the conformational changes that occur during a peptide elongation cycle of NRPSs are not limited to structural methods alone. There has been significant contributions from the Mootz group using a FRET-engineered A-T didomain to disentangle the various subdomain movements that occur upon substrate binding, adenylation, and transfer to the phosphopantetheine (Ppant) prosthetic group of the carrier protein. Recently, a C-A-T elongation module containing a FRET sensor was generated, and through hydrogen-deuterium exchange mass spectrometry and photolabile steric caging, it was confirmed that multiple enzyme conformations can exist in the bulk reaction mixture. In total, sampling the conformational shifts of multidomain NRPS proteins in solution has revealed that specific substrate binding and transformation events can shift the T domain's affinity for neighboring A and C domains in the direction of templated biosynthesis.