it has also been demonstrated that sos response dependent accumulation of mutation during replication of dna that has not been attacked by exogenous dna damaging factors can be seen in challenged cells, termed as sos untargeted mutation 而在出現(xiàn)sos反應的細胞中還觀察到了在復制過程中的產(chǎn)生的、發(fā)生在沒有外源損傷dna上的突變事件,被稱為sos非定標性突變。
in e coli, dna polymerases are key enzymes involved in two distinguished pathways contributing to untargeted mutagenesis . replication of dna by pol v ( umuc ), in the presence of umud1, reca and single strand binding protein ( ssb ), is highly mutagenic and exhibits a predominant mutation pattern of base transversion . another error prone polymerase involved in untargeted mutagenesis is pol iv, encoded by dinb gene 在umud',reca和單鏈結合蛋白ssb的協(xié)助下,polv(umuc)能在單鏈模板上催化dna合成并產(chǎn)生高頻率的以堿基顛換為主要形式的突變;另一個與非定標性突變有關的易誤dna聚合酶是pol,為dinb基因的編碼產(chǎn)物。