. "At the beginning of this reaction, 1 molecule of 'Transcription-coupled (TC) repair complex', and 1 molecule of 'damaged DNA substrate:nascent mRNA hybrid with 3' incision' are present. At the end of this reaction, 1 molecule of 'Transcription-coupled (TC) repair complex', 1 molecule of 'excised DNA fragment with lesion', and 1 molecule of 'damaged DNA substrate:nascent mRNA hybrid with dual incisions' are present.

This reaction takes place in the 'nucleus' and is mediated by the 'endodeoxyribonuclease activity' of 'Transcription-coupled (TC) repair complex'.
"^^ . . . . . . "5' incision leading to excision of DNA fragment with lesion in TC-NER"^^ . . . . . .