Low-fidelity DNA polymerase with a helicase activity that promotes microhomology-mediated end-joining (MMEJ), an alternative non-homologous end-joining (NHEJ) machinery required to repair double-strand breaks in DNA during mitosis . MMEJ is an error-prone repair pathway that produces deletions of sequences from the strand being repaired and promotes genomic rearrangements, such as telomere fusions, some of them leading to cellular transformation . MMEJ is required during mitosis to repair persistent double-strand breaks that originate in S-phase . Although error-prone, MMEJ protects against chromosomal instability and tumorigenesis (By similarity). The polymerase acts by binding directly the 2 ends of resected double-strand breaks, allowing microhomologous sequences in the overhangs to form base pairs . It then extends each strand from the base-paired region using the opposing overhang as a template . Requires partially resected DNA containing 2 to 6 base pairs of microhomology to perform MMEJ . The polymerase lacks proofreading activity and is highly promiscuous: unlike most polymerases, promotes extension of ssDNA and partial ssDNA (pssDNA) substrates . When the ends of a break do not contain terminal microhomology must identify embedded complementary sequences through a scanning step . Also acts as a DNA helicase, promoting dissociation of the replication protein A complex (RPA/RP-A), composed of RPA1, RPA2 and RPA3, from resected double-strand breaks to allow their annealing and subsequent joining by MMEJ . Removal of RPA/RP-A complex proteins prevents RAD51 accumulation at resected ends, thereby inhibiting homology-recombination repair (HR) pathway . Also shows RNA-directed DNA polymerase activity to mediate DNA repair in vitro; however this activity needs additional evidence in vivo . May also have lyase activity . Involved in somatic hypermutation of immunoglobulin genes, a process that requires the activity of DNA polymerases to ultimately introduce mutations at both A/T and C/G base pairs (By similarity). POLQ-mediated end joining activity is involved in random integration of exogenous DNA hampers . .

o75417

DNA polymerase theta (DNA polymerase eta) [Includes: Helicase POLQ (EC 3.6.4.12); DNA polymerase POLQ (EC 2.7.7.7) (RNA-directed DNA polymerase POLQ) (EC 2.7.7.49)],POLQ POLH,POLH, DNA polymerase eta, DNA polymerase theta, POLQ

Human

WB,IHC,ELISA

WB 1:500-1:2000
IHC 1:50-1:300
ELISA 1:5000-1:20000

290kD

Rabbit

Recombinant Human POLQ (Met1-Met894).

Polyclonal

IgG

Purified by antigen affinity column.

0.01M PBS, pH 7.4, 50% Glycerol, 0.05% Proclin 300.

Use a manual defrost freezer and avoid repeated freeze-thaw cycles. Store at 4℃ short term (1-2 weeks). Store at -20℃ 12 months.