question: Are there any functional differences between Mfd and its human Cocaine syndrome protein B (CSB) homolog?
answer: Both Cockayne syndrome protein B (CSB) and Mfd are involved in transcription-coupled repair. CSB is the human TCR coupling factor and Mfd is the bacterial TCR coupling factor. However, unlike Mfd, CSB does not act as a helicase nor does it dissociate stalled RNA polymerase II, suggesting a coupling mechanism in humans different from that in prokaryotes. Moreover, Mfd may be functionally distinct from its human CSB homolog in that it does not detectably contribute to the recovery of gene expression or global repair following oxidative damage.