DNA damage that blocks the transcription of genes is prioritized for repair by 
transcription-coupled DNA repair pathways. RNA polymerases stalled at DNA 
lesions obstruct repair enzymes, but this situation is turned to the advantage 
of the cell by transcription-repair coupling factors that remove the stalled RNA 
polymerase from DNA and increase the rate at which the lesion is repaired. 
Recent structural studies of the bacterial transcription-repair coupling factor, 
Mfd, have revealed a modular architecture in which an ATP-dependent DNA-based 
motor is coupled to protein-protein interaction domains that can attach the 
motor to RNA polymerase and the DNA repair protein UvrA. Here I review the key 
features of this multifunctional protein and discuss how recent mechanistic and 
structural findings have advanced our understanding of transcription-coupled DNA 
repair in bacteria.