DNA Polymerase Theta
From Proteopedia
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== Function == | == Function == | ||
| - | DNA polymerase theta is a DNA double strand break repair protein. | + | |
| + | DNA polymerase theta (pol theta) is a DNA double strand break repair protein. Double strand breaks can occur as a result of both exogenous (ionizing radiation) and endogenous (reactive oxygen species, replication fork collapse) damage. To repair breaks, polymerase theta employs theta-mediated end-joining (TMEJ), which is a form of alternative non-homologous end-joining (alt-NHEJ). TMEJ begins with pairing of microhomologies in 3' single stranded overhangs that have been exposed through 5' end resectioning at the site of the break. If the microhomologies are internal to the 3' end of the overhanging DNA, the resulting flaps will be removed and a deletion will be introduced. If microhomologies arise from brief templated synthesis with a more distant strand, insertions will be introduced. Once microhomologies are aligned, pol theta synthesizes DNA to fill the gaps on either side of the microhomologies. | ||
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==Structural Description== | ==Structural Description== | ||
<Structure load='4x0p' size='350' frame='true' align='right' caption='DNA polymerase theta polymerase domain in complex with double-stranded DNA substrate and incoming ddATP' > | <Structure load='4x0p' size='350' frame='true' align='right' caption='DNA polymerase theta polymerase domain in complex with double-stranded DNA substrate and incoming ddATP' > | ||
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You may include any references to papers as in: the use of JSmol in Proteopedia <ref>DOI 10.1002/ijch.201300024</ref> or to the article describing Jmol <ref>PMID:21638687</ref> to the rescue. | You may include any references to papers as in: the use of JSmol in Proteopedia <ref>DOI 10.1002/ijch.201300024</ref> or to the article describing Jmol <ref>PMID:21638687</ref> to the rescue. | ||
Revision as of 01:41, 29 April 2020
Function
DNA polymerase theta (pol theta) is a DNA double strand break repair protein. Double strand breaks can occur as a result of both exogenous (ionizing radiation) and endogenous (reactive oxygen species, replication fork collapse) damage. To repair breaks, polymerase theta employs theta-mediated end-joining (TMEJ), which is a form of alternative non-homologous end-joining (alt-NHEJ). TMEJ begins with pairing of microhomologies in 3' single stranded overhangs that have been exposed through 5' end resectioning at the site of the break. If the microhomologies are internal to the 3' end of the overhanging DNA, the resulting flaps will be removed and a deletion will be introduced. If microhomologies arise from brief templated synthesis with a more distant strand, insertions will be introduced. Once microhomologies are aligned, pol theta synthesizes DNA to fill the gaps on either side of the microhomologies.
Structural Description
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