Rev1 is a deoxycytidyl transferase involved in translesion DNA synthesis (TLS) pathway to bypass DNA lesions during replication []. During TLS, Y-family DNA polymerase (Poleta, Polkappa, Poliota and Rev1) incorporates a nucleotide opposite the DNA lesion, and then Polzeta (consitst of Rev3 and Rev7) carries out primer extension. Rev1 is a unique member of the Y polymerase family, since its catalytic activity is limited to DNA-dependent, deoxycytidyl transferase activity [, , ].
This entry represents the C-terminal domain of DNA repair protein Rev1, an enzyme which allows DNA synthesis to proceed even in the presence of DNA damage. Rev1 belongs to the Y-family of TLS polymerases. Rev1 possess a limited catalytic activity but it has a second and more important function which involved the recruitment and coordination of other Y-family TLS polymerases and the regulatory subunit Rev7 of the B-family polymerase pol. This interaction is mediated by its C-terminal domain which therefore serves as a scaffold that allows access of the Y-family polymerases to their cognate DNA lesions and the subsequent exchange to pol, which then extends the distorted DNA primer terminus opposite the lesion [, ]. This domain adopts a four-helix bundle that interacts with Rev7, Polkappa and Poleta. However, the Rev7-binding interface is distinct from the binding site of DNA polymerase eta or kappa [, ].
This entry represents the C-terminal domain of DNA repair protein Rev1, an enzyme which allows DNA synthesis to proceed even in the presence of DNA damage. Rev1 belongs to the Y-family of TLS polymerases. Rev1 possess a limited catalytic activity but it has a second and more important function which involved the recruitment and coordination of other Y-family TLS polymerases and the regulatory subunit Rev7 of the B-family polymerase pol. This interaction is mediated by its C-terminal domain which therefore serves as a scaffold that allows access of the Y-family polymerases to their cognate DNA lesions and the subsequent exchange to pol, which then extends the distorted DNA primer terminus opposite the lesion [, ]. This domain adopts a four-helix bundle that interacts with Rev7, Polkappa and Poleta. However, the Rev7-binding interface is distinct from the binding site of DNA polymerase eta or kappa [, ].
In Escherichia coli, UV and many chemicals appear to cause mutagenesis by a process of translesion synthesis that requires DNA polymerase III and the SOS-regulated proteins UmuD, UmuC and RecA. This machinery allows the replication to continuethrough DNA lesion, and therefore avoid lethal interruption of DNA replication after DNA damage []. UmuC is a well conserved protein in prokaryotes, with a homologue in yeast species.Proteins known to contain an UmuC domain are listed below: E. coli MucB protein. Plasmid-born analogue of the UmuC protein.Saccharomyces cerevisiae (Baker's yeast) Rev1 protein. Homologue of UmuC also required for normal induction of mutations by physical and chemical agents. Salmonella typhimurium ImpB protein. Plasmid-born analogue of the UmuC protein.Bacterial UmuC protein.E. coli DNA-damage-inducible protein P (DinP).S. typhimurium SamB homologue of UmuC plasmid associated.
This entry represents the little finger domain superfamily found in Y-family (lesion bypass) DNA polymerases. Y-family polymerases were originally known as UmuC/DinB/Rev1/Rad30 after each branch of the family. These enzymes are characterised by their low-fidelity synthesis on undamaged DNA templates and by their ability to traverse replication-blocking lesions. By contrast, high-fidelity polymerases (such as DNA polymerase III) are sensitive to distortions in the DNA template. As a result, Y-family polymerases can extend primer strands across DNA strand lesions that would otherwise stall replicative polymerases. To minimize mutations through their low fidelity synthesis, these enzymes are regulated, and are thought to interact with processivity factors, β-clamp or proliferating cell nuclear antigen (PCNA), which are also essential for the function of replicative DNA polymerases []. Organisms can contain more than one Y-family polymerase, each with a unique DNA damage bypass and fidelity profile. For example, humans posses four Y-family polymerases: DNA polymerases kappa, iota, eta and Rev1. Y-family polymerases show no homology to DNA polymerases from the A-, B-, C-, D- or X-families []. The Y-family of DNA polymerases includes the following enzymes:Prokaryotic DNA polymerase IV (DinB) [].Archaeal DinB homologue DNA polymerase IV [].Eukaryotic DinB homologue DNA polymerase kappa [].Prokarytoic DNA repair proteins UmuC and UmuD [].Eukaryotic Rad30 homologues DNA polymerase eta and iota [, ].Eukaryotic DNA repair protein Rev1 [].Human DNA polymerase kappa is a right-handed shaped molecule with palm, fingers, thumb, little finger and wrist subdomains []. The little finger domain has a beta-α-β(2)-α-β fold with antiparallel β-sheet and a reversed ferredoxin-like topology.
This entry represents the little finger domain found in Y-family (lesion bypass) DNA polymerases. Y-family polymerases were originally known as UmuC/DinB/Rev1/Rad30 after each branch of the family. These enzymes are characterised by their low-fidelity synthesis on undamaged DNA templates and by their ability to traverse replication-blocking lesions. By contrast, high-fidelity polymerases (such as DNA polymerase III) are sensitive to distortions in the DNA template. As a result, Y-family polymerases can extend primer strands across DNA strand lesions that would otherwise stall replicative polymerases. To minimize mutations through their low fidelity synthesis, these enzymes are regulated, and are thought to interact with processivity factors, β-clamp or proliferating cell nuclear antigen (PCNA), which are also essential for the function of replicative DNA polymerases []. Organisms can contain more than one Y-family polymerase, each with a unique DNA damage bypass and fidelity profile. For example, humans posses four Y-family polymerases: DNA polymerases kappa, iota, eta and Rev1. Y-family polymerases show no homology to DNA polymerases from the A-, B-, C-, D- or X-families []. The Y-family of DNA polymerases includes the following enzymes:Prokaryotic DNA polymerase IV (DinB) [].Archaeal DinB homologue DNA polymerase IV [].Eukaryotic DinB homologue DNA polymerase kappa [].Prokarytoic DNA repair proteins UmuC and UmuD [].Eukaryotic Rad30 homologues DNA polymerase eta and iota [, ].Eukaryotic DNA repair protein Rev1 [].Human DNA polymerase kappa is a right-handed shaped molecule with palm, fingers, thumb, little finger and wrist subdomains [].
