Segmental isotopic labelling of a multidomain protein by protein ligation by protein trans-splicing

Structure–function relationships of intact multidomain proteins: Segmental isotopic labelling of multidomain proteins could open a new avenue for studying particular domains in intact proteins, because it could simplify the NMR spectra through the incorporation of stable isotopes in a region-specific manner. We have demonstrated that the necessary protein ligation can be easily achieved both in vivo and in vitro by protein trans-splicing.