The present disclosure relates to base-editing systems including a fusion protein including a DNA-binding domain and a cytidine deaminase domain and a non-protein uracil-DNA glycosylase inhibitor, and methods of using the same. The DNA-binding domains of base-editing systems of the present disclosure include domains with a variety of target region possibilities, which increase the number and type of sequences that can be edited. The npUGIs of the base-editing systems of the present disclosure improve UDG inhibition (e.g., UDG inhibition is more complete) and are suitable for use in a wide range of organisms.