4fjo | pdb_00004fjo
Structure of the Rev1 CTD-Rev3/7-Pol kappa RIR complex
Structural highlights
Function[DPOLZ_MOUSE] Interacts with MAD2L2 to form the error prone DNA polymerase zeta involved in translesion DNA synthesis (By similarity). [REV1_MOUSE] Deoxycytidyl transferase involved in DNA repair. Transfers a dCMP residue from dCTP to the 3'-end of a DNA primer in a template-dependent reaction. May assist in the first step in the bypass of abasic lesions by the insertion of a nucleotide opposite the lesion. Required for normal induction of mutations by physical and chemical agents.[1] [MD2L2_MOUSE] Adapter protein able to interact with different proteins and involved in different biological processes. Mediates the interaction between the error-prone DNA polymerase zeta catalytic subunit REV3L and the inserter polymerase REV1, thereby mediating the second polymerase switching in translesion DNA synthesis. Translesion DNA synthesis releases the replication blockade of replicative polymerases, stalled in presence of DNA lesions. May also regulate another aspect of cellular response to DNA damage through regulation of the JNK-mediated phosphorylation and activation of the transcriptional activator ELK1. Inhibits the FZR1- and probably CDC20-mediated activation of the anaphase promoting complex APC thereby regulating progression through the cell cycle. Regulates TCF7L2-mediated gene transcription and may play a role in epithelial-mesenchymal transdifferentiation (By similarity). [POLK_MOUSE] DNA polymerase specifically involved in DNA repair. Plays an important role in translesion synthesis, where the normal high-fidelity DNA polymerases cannot proceed and DNA synthesis stalls. Depending on the context, it inserts the correct base, but causes frequent base transitions, transversions and frameshifts. Lacks 3'-5' proofreading exonuclease activity. Forms a Schiff base with 5'-deoxyribose phosphate at abasic sites, but does not have lyase activity (By similarity).[2] Publication Abstract from PubMedDNA synthesis across lesions during genomic replication requires concerted actions of specialized DNA polymerases in a potentially mutagenic process known as translesion synthesis. Current models suggest that translesion synthesis in mammalian cells is achieved in two sequential steps, with a Y-family DNA polymerase (kappa, eta, iota, or Rev1) inserting a nucleotide opposite the lesion and with the heterodimeric B-family polymerase zeta, consisting of the catalytic Rev3 subunit and the accessory Rev7 subunit, replacing the insertion polymerase to carry out primer extension past the lesion. Effective translesion synthesis in vertebrates requires the scaffolding function of the C-terminal domain (CTD) of Rev1 that interacts with the Rev1-interacting region of polymerases kappa, eta, and iota and with the Rev7 subunit of polymerase zeta. We report the purification and structure determination of a quaternary translesion polymerase complex consisting of the Rev1 CTD, the heterodimeric Pol zeta complex, and the Pol kappa Rev1-interacting region. Yeast two-hybrid assays were employed to identify important interface residues of the translesion polymerase complex. The structural elucidation of such a quaternary translesion polymerase complex encompassing both insertion and extension polymerases bridged by the Rev1 CTD provides the first molecular explanation of the essential scaffolding function of Rev1 and highlights the Rev1 CTD as a promising target for developing novel cancer therapeutics to suppress translesion synthesis. Our studies support the notion that vertebrate insertion and extension polymerases could structurally cooperate within a megatranslesion polymerase complex (translesionsome) nucleated by Rev1 to achieve efficient lesion bypass without incurring an additional switching mechanism. Structural basis of Rev1-mediated assembly of a quaternary vertebrate translesion polymerase complex consisting of Rev1, heterodimeric polymerase (Pol) zeta, and Pol kappa.,Wojtaszek J, Lee CJ, D'Souza S, Minesinger B, Kim H, D'Andrea AD, Walker GC, Zhou P J Biol Chem. 2012 Sep 28;287(40):33836-46. Epub 2012 Aug 2. PMID:22859295[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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