5-formylcytosine and 5-carboxylcytosine reduce the rate and substrate specificity of RNA polymerase II transcription

A systematic in vitro analysis of five different forms of cytosine in mammalian and yeast RNA polymerase II (Pol II) transcription demonstrates that Pol II can read and distinguish subtle differences in modified cytosines and process them differently, suggesting a putative functional interplay between cytosine modification status and transcription.