DNA polymerase theta is an enzyme that in humans is encoded by the POLQ gene. This polymerase plays a key role in one of the three major double strand break repair pathways: theta-mediated end joining. Most double-strand breaks are repaired by non-homologous end joining (NHEJ) or homology directed repair (HDR). However, in some contexts, NHEJ and HR are insufficient and TMEJ is the only solution to repair the break. TMEJ is often described as alternative NHEJ, but differs in that it lacks a requirement for the Ku heterodimer, and it can only act on resected DNA ends. Following annealing of short (i.e., a few nucleotides) regions on the DNA overhangs, DNA polymerase theta catalyzes template-dependent DNA synthesis across the broken ends, stabilizing the paired structure. Here you can see a crystal structure of the human polymerase theta in complex with a synthetic DNA molecule (PDB code: 6XBU)
#molecularart ... #immolecular ... #DNApol ... #theta ... #Xray ... #DNArepair ... Rendered with @proteinimaging and finished with @corelphotopaint
#molecularart ... #immolecular ... #DNApol ... #theta ... #Xray ... #DNArepair ... Rendered with @proteinimaging and finished with @corelphotopaint
