Polymerase

REV1 Polymerase (REV1) contains a BRCT domain, which is imperative in protein-protein interactions. REV1 is a deoxycytidyl transferase involved in DNA repair. REV1 assists in the 1st step in the bypass of abasic lesions by the incorporation of a nucleotide opposite the lesion. REV1 is essential for normal generation of mutations by physical and chemical agents. REV1 transfers a dCMP residue from dCTP to the 3'-end of a DNA primer in a template-dependent reaction. A role for the human Rev1-like protein has been suggested as a scaffold which recruits DNA polymerases involved in translesion synthesis (TLS) of damaged DNA.

Polymerase III Polypeptide K, known as PORL3K, is a small vital subunit of RNA polymerase III. The carboxy-terminal domain of PORL3K owns a sequence which is very similar to the carboxy-terminal domain of an RNA polymerase II elongation factor. PORL3K takes part in sensing and limiting infection by intracellular bacteria and DNA viruses. PORL3K is also plays a role as nuclear and cytosolic DNA sensor which takes part in the innate immune response.

Polymerase III Polypeptide F (POLR3F) is a member of the eukaryotic RPC34/RPC39 RNA polymerase subunit family. POLR3F is DNA-dependent RNA polymerase which catalyzes the transcription of DNA into RNA using the 4 ribonucleoside triphosphates as substrates. POLR3F is one of many subunits forming eukaryotic RNA polymerase III (RNA Pol III), which transcribes 5S ribosomal RNA and tRNA genes. POLR3F binds both TFIIIB90 and TBP, 2 subunits of RNA polymerase III transcription initiation factor IIIB (TFIIIB).

POLR2J2 belongs to the RNA polymerase II subunit 11 gene family, that includes 3 genes in a cluster on chromosome 7q22.1 and a pseudogene on chromosome 7p13. DNA directed RNA polymerase II polypeptide J family encodes a subunit of RNA polymerase II, the polymerase which is responsible for synthesizing messenger RNA in eukaryotes. This locus produces multiple, otherwise spliced transcripts which express isoforms with distinct C-termini compared to DNA directed RNA polymerase II polypeptide J. Most or all variants are spliced to include additional non-coding exons at the 3' end that makes them candidates for nonsense-mediated decay (NMD). Therefore, it is unknown if this locus expresses a protein or proteins in vivo.

Polymerase II Polypeptide I (POLR2I) is a member of the archaeal RpoM/eukaryotic RPA12/RPB9/RPC11 RNA polymerase family. POLR2I is a subunit of RNA polymerase II, which is a polymerase responsible for synthesizing messenger RNA in eukaryotes. DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the 4 ribonucleoside triphosphates as substrates. In addition POLR2I synthesizes mRNA precursors and numerous functional non-coding RNAs.

Polymerase II Polypeptide F (POLR2F) is the 6th largest subunit of RNA polymerase II, the polymerase responsible for synthesizing messenger RNA in eukaryotes, which is also shared by the other two DNA-directed RNA polymerases. In yeast, POLR2F, in combination with at least 2 other subunits, forms a structure which stabilizes the transcribing polymerase on the DNA template. DNA-dependent RNA polymerases catalyze the transcription of DNA into RNA via the 4 ribonucleoside triphosphates as substrates. Pol II is the principal element of the basal RNA polymerase II transcription apparatus. Pols are comprised of mobile elements which move close to each other. In Pol II, POLR2F/RPB6 is part of the clamp element and along with parts of RPB1 and RPB2 constructs a compartment to which the RPB4-RPB7 subcomplex attaches.

DNA-directed RNA polymerases I, II, and III subunit RPABC1 (POLR2E) is a member of the archaeal RpoH/eukaryotic RPB5 RNA polymerase subunit family. POLR2E being a DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the 4 ribonucleoside triphosphates as substrates. POLR2E is the 5th largest subunit of RNA polymerase II (the polymerase which is responsible for synthesizing messenger RNA in eukaryotes). The POLR2E subunit is shared by the other 2 DNA-directed RNA polymerases and is present in two-fold molar excess over the other polymerase subunits. An interaction between the POLR2E subunit and a hepatitis virus transactivating protein has been established, suggesting that an interaction between transcriptional activators and the polymerase can occur through the POLR2E subunit.

Polymerase II Polypeptide D (POLR2D) is a member of the eukaryotic RPB4 RNA polymerase subunit family. POLR2D is the fourth largest subunit of RNA polymerase II. Pol II is the main element of the basal RNA polymerase II transcription machinery. polymerase is responsible forsynthesizing messenger RNA in eukaryotes. In yeast, POLR2D subunit is connected with the polymeraseunder suboptimal growth conditions and might have a stress protective role. POLR2D catalyzes the transcription of DNA into RNA by the 4 ribonucleoside triphosphates as substrates.

DNA polymerase POLL is involved in base excision repair (BER). POLL is a low-fidelity polymerase that takes part in both spontaneous and DNA damage-induced mutagenesis. Furthermore, POLL takes part in the mutagenic bypass of T-T dimers. Pol lambda possesses terminal transferase and 5’-deoxyribose-5-phosphate lyase activity which is synchronized by PCNA and replication protein A.

TAF9 is a universal transcription factor which enables the preinitiation complex assembly by direct interactions with the TATA promoter element. TAF9 is a multisubunit complex consisting of a small TATA-binding polypeptide and other TBP-associated factors (TAFs) and performs as a channel for regulatory signals.

TAF10 is a small subunit of TFIID which is related to a subdivision of TFIID complexes. Studies with human and mammalian cells verified that this subunit is mandatory for transcriptional activation by the estrogen receptor, for progression through the cell cycle, and is essential for several cellular differentiation programs.

T7 RNA polymerase active enzyme synthesizes RNA at an increasing degree of that of E. coli RNA polymerase and it terminates transcription often. T7 RNA polymerase is very selective for initiation at its own promoter sequences and is resistant to antibiotics that inhibit E. coli RNA polymerase. In-vitro transcription of mRNA is achieved via bacteriophage T7 RNA polymerase using its ability to produce full-length RNA transcripts with high reliability, thoughT7 RNAP can manufacture as well immunostimulatory by products for example dsRNA which affect protein expression.

Poly (ADP-Ribose) Polymerase 2 (PARP2) contains a catalytic domain which is homologous to that of poly (ADP-ribosyl) transferase but lacks an N-terminal DNA binding domain which activates the C-terminal catalytic domain of poly (ADP-ribosyl) transferase. PARP2 is capable of catalyzing a poly (ADP-ribosyl)ation reaction. The basic residues within the N-terminal area of this protein can bear potential DNA-binding properties, and can be engaged in the nuclear and/or nucleolar targeting of the protein. There has been found two alternatively spliced transcript variants encoding distinct isoforms.

PARP1 takes part in the base excision repair pathway, by catalyzing the poly ADP-ribosyl of a restricted number of acceptor proteins involved in chromatin architecture and in DNA metabolism.. PARP1 mediates the poly ADP-ribosy of APLF and CHFR. PARP1 positively regulates the transcription of MTUS1 and negatively regulates the transcription of MTUS2/TIP150. PARP1 is a chromatin-associated enzyme, poly (ADP-ribosyl) transferase, which modifies various nuclear proteins by poly ADP-ribosyl. PARP1 takes part in the regulation of various significant cellular processes such as differentiation, proliferation, and tumor transformation and also in the regulation of the molecular events involved in the recovery of cell from DNA damage. PARP1 is a site of mutation in Fanconi anemia, and is involved in the pathophysiology of type I diabetes.