UV-stimulated scaffold protein A

Factor involved in transcription-coupled nucleotide excision repair (TC-NER), a mechanism that rapidly removes RNA polymerase II-blocking lesions from the transcribed strand of active genes. Facilitates the ubiquitination of the elongating form of RNA polymerase II (RNA pol IIo) at DNA damage sites, thereby promoting RNA pol IIo backtracking and access by the TC-NER machinery to lesion sites. Acts by promoting stabilization of ERCC6 by recruiting deubiquitinating enzyme USP7 to TC-NER complexes, preventing UV-induced degradation of ERCC6 by the proteasome. Also facilitates transfer of TFIIH to RNA polymerase II. Not involved in processing oxidative damage.