Members of the pentatricopeptide repeat (PPR) protein family catalyse targeted cytidine to uridine RNA editing in land plants. These proteins contain of a scaffold of helix-turn-helix PPR domains, which recognise RNA in a single domain to single base manner following a well-elucidated code. A cytidine deaminase-like domain at the C-terminus of some PPR editing factors is the catalytic domain in the process. From this basic scaffold, a novel RNA editing factor has been designed to evaluate the potential for biotechnological applications using this system. Here, we describe the RNA binding and editing specificity for this factor, as well as the outcomes of using size exclusion chromatography coupled synchrotron small angle X-ray scattering as a characterisation tool. In particular, the SAXS experiments provide information regarding the stoichiometry of complexes containing this designer RNA editing factor and allow refinement of dynamic models built by homology and ab initio modelling.