DNA修复和重组生化总结12.5

DNA修复1.在Ecoli中DNA修复的四种类型。Types of DNA Repair System in E.Coli·Mismatch repairBase-excision repairNucleotide-excision repairDirect repair我觉得错配修复过程算比较复杂，涉及的蛋白多，而且还有一个修复识别链（半甲基化机制)。要能用自己的语言描述这个修复过程，（可能会考个大题），知道涉及的蛋白质的作用，可能会拿出来考个名词解释，你就解释他的作用就好了。Proteins Required for Methyl-Directed Mismatch RepairDam methylaseMutH,MutL,MutS proteinsDNA helicase llSSBDNA polymerase lllMismatchesExonuclease IExonuclease VllRec」nucleaseExonuclease XDNA ligase其他三种修复也要知道它的过程和机理。3.细菌中的跨损伤修复，知道它的原理和产生的原因（特别损失的情况下不得已），我们去年考了判断题。4.这种总结就容易出选择填空判断SummaryMismatch repair in E.Coli is directed by transient nonmethylation of the (S')GATC sequence on thenewly synthesized strand.Base-poocision rpair syste ms recognize and repair damage caused by anironmental reagents andspontaneous roaction of nucleotides.Nucleotide-excision repair systems and remove a variety of bulky lesion and pyrimidinedimers.Direct repair system works through direct reversal of the reaction causing the damage.In bacteria,error-prone translesion DNA synthesis occurs in response to very heavy DNA damageTwo ways to repair double-strand breaks:nonhomologous end joining and homologous recombination.