耐辐射球菌中priA类似基因突变对DNA修复和DNA转化的影响  

EFFECT OF priA like GENE MUTATION ON DNA REPAIR AND DNA TRANSFORMATION OF Deinococcus radiodurans

作　　者：王媛[1] 华跃进[1] 

机构地区：[1]浙江大学原子核农业科学研究所/农业部核农学重点开放实验室,浙江杭州310029

出　　处：《核农学报》2012年第1期73-79,共7页Journal of Nuclear Agricultural Sciences

基　　金：国家"863"项目(2007AA021305);国家自然科学基金重点资助项目(30830006);重大新药创制科技重大专项(2009ZXJ09001-034);转基因生物新品种培育重大专项项目(2009ZX08009-075B);农业部行业专项(200803034)

摘　　要：DNA损伤很易阻断复制叉的前进。损伤DNA的修复以及接下来停止复制叉的重启动过程对细胞生存极为重要。依赖于PriA的复制重启动机制是细菌复制重启动的主要途径。为了解priA类似基因Dr2606在耐辐射球菌中的作用,并检测Dr2606在DNA修复中的作用,本研究用卡那霉素抗性基因代替Dr2606阅读框,构建了Dr2606缺失突变株,并对突变株进行UV和丝裂霉素处理,测定了Dr2606突变株的转化效率。Dr2606的突变导致菌体生长缓慢,细胞生存率急剧下降。意外的是,耐辐射球菌的DNA修复能力没有削弱。但突变株的转化效率大大削弱。这说明在耐辐射球菌中priA类似基因Dr2606对停止复制叉的重启动过程并不是必需的;耐辐射球菌不依赖于原点的复制重启动过程可能与其他细菌不同。Replication fork progression can be blocked easily by DNA damage. Damaged DNA repair and the subsequent restart of the stalled or collapsed replication forks are critical for cell survival. The PriA-dependent pathway is the major replication restart mechanism in bacteria. To understand the roles of a priA-like gene （Dr2606） in Deinococcus radiodurans and DNA repair, a Dr2606 null mutant was constructed by replacing Dr2606 open reading frame with a kanamycin-resistanee gene and treated the Dr2606 mutant with UV and mitomycin C （MMC）, and the DNA transformation efficiency of the Dr2606 mutant was also tested. Successively, the Dr2606 mutant showed a delayed growth and a dramatic decrease of cell viability. Unexpectedly, the DNA repair capability of D. radiodurans was not impaired by the inactivation of Dr2606. However, the DNA transformation efficiency was largely compromised in the mutant. These results indicate that the priA-like gene （Dr2606） is dispensable for stalled DNA replication forks restart in D. radiodurans and origin-independent replication restart in D. radiodurans may be different from other bacteria.

关 键 词：PRIA 耐辐射球菌 DNA修复 DNA转化效率 

分 类 号：Q937[生物学—微生物学]