<P> Replication protein A (RPA) and XPA are the last two proteins associated with the main NER repair complex . These two proteins are present prior to TFIIH binding since they are involved with verifying DNA damage . They may also protect single - stranded DNA . After verification, the 5' side incision is made and DNA repair begins before the 3' side incision . This helps reduce exposed single stranded DNA during the repair process . </P> <P> Replication factor C (RFC) loads the Proliferating Cell Nuclear Antigen (PCNA) onto the DNA strand . This allows DNA polymerases implicated in repair (δ, ε and / or κ) to copy the undamaged strand via translocation . DNA ligase I and Flap endonuclease 1 or the Ligase - III - XRCC1 complex seal the nicks to complete NER . </P> <P> The process of nucleotide excision repair is controlled in Escherichia coli by the UvrABC endonuclease enzyme complex, which consists of four Uvr proteins: UvrA, UvrB, UvrC, and DNA helicase II (sometimes also known as UvrD in this complex). First, a UvrA - UvrB complex scans the DNA, with the UvrA subunit recognizing distortions in the helix, caused for example by pyrimidine dimers . When the complex recognizes such a distortion, the UvrA subunit leaves and an UvrC protein comes in and binds to the UvrB monomer and, hence, forms a new UvrBC dimer . UvrB cleaves a phosphodiester bond 4 nucleotides downstream of the DNA damage, and the UvrC cleaves a phosphodiester bond 8 nucleotides upstream of the DNA damage and created 12 nucleotide excised segment . DNA helicase II (sometimes called UvrD) then comes in and removes the excised segment by actively breaking the hydrogen bonds between the complementary bases . The resultant gap is then filled in using DNA polymerase I and DNA ligase . The basic excision process is very similar in higher cells, but these cells usually involve many more proteins--E. coli is a simple example . </P> <P> TC - NER also exists in bacteria, and is mediated by the TRCF (Mfd) protein . TRCF is an SF2 ATPase that uses ATP hydrolysis to translocate on dsDNA upstream of the transcription bubble and forward translocate RNA polymerase, thus initiating dissociation of the RNA Polymerase ternary elongation complex . TRCF also recruits the Uvr (A) BC nucleotide excision repair machinery by direct physical interaction with the UvrA subunit . </P>

During nucleotide excision repair in e. coli which proteins identify the damaged dna
find me the text answering this question