DNA-binding protein which is required for efficient transcription-coupled nucleotide excision repair (TC-NER) (PubMed:38252411, PubMed:38890355, PubMed:39353615, PubMed:39547223, PubMed:39547228, PubMed:39547229). Acts as part of a TC-NER complex which assembles and interacts with RNA polymerase II (RNAPII) when it stalls at DNA lesions (PubMed:39547223, PubMed:39547228, PubMed:39547229). TC-NER complex subunit UVSSA binds to the GTF2H1/p62 subunit of the TFIIH transcription factor complex, tethering TFIIH to the TC-NER complex (PubMed:39547228). WHR1/STK19 then interacts with the XPD helicase subunit of TFIIH which guides TFIIH to DNA downstream of the stalled RNAPII, ensuring DNA repair (PubMed:39353615, PubMed:39547228, PubMed:39547229). Directly interacts with RNAPII and also binds to downstream DNA (PubMed:39547229).