Bacterial YedK represses plasmid DNA replication and transformation through its DNA single-strand binding activity
Bacterial YedK represses plasmid DNA replication and transformation through its DNA single-strand binding activity
复制标题
细菌 YedK 通过其 DNA 单链结合活性抑制质粒 DNA 复制和转化
DOI：
10.1016/j.micres.2021.126852
复制
发表时间：
2021
影响因子：
6.7
通讯作者：
Xinyi He
中科院分区：
文献类型：
--
作者：
Wenyue Hu;Yuli Wang;Bingxu Yang;Chen Lin;Hao Yu;Guang Liu;Zixin Deng;Hong-Yu Ou;Xinyi He
SOS反应相关多肽酶(SRAP)是一个古老的蛋白质超家族，存在于生命的各个领域。最近有报道哺乳动物的SRAP与单链DNA中的基本位点(AP)共价结合以保护染色体的完整性。YedK，Escherichia coliSRAP，没有功能特征。在这里，我们报道了细菌细胞裂解物中YedK的偶然下拉，当加入单链DNA时，观察到YedK的进一步浓缩。YedK能与多种DNA底物结合，特别是对单链DNA双链有很高的亲和力。作为一种SRAP蛋白，YedK在SOS反应中的作用已被广泛研究，但在紫外线和各种DNA损伤剂的处理下，EscherichiaKedk突变株与野生型菌株没有差异，表明它不是必需的或多余的。Coli.令人惊讶的是，来自大肠埃希菌和肠毛萨蒙氏菌的yedK突变体显示出比野生型更高的质粒DNA转化效率。与此相对应，YedK的诱导有效地降低了质粒DNA的拷贝数。YedK的定点突变表明，参与单链DNA结合的残基和N端2位的半胱氨酸残基可以解除对转化效率的抑制。
The SOS response-associated peptidase (SRAP) is an ancient protein superfamily in all domains of life. The mammalian SRAP was recently reported to covalently bind to the abasic sites (AP) in single stranded (ss) DNA to shield the chromosome integrity. YedK, theEscherichia coliSRAP, is not functionally characterized. Here we report the fortuitous pull-down of YedK from bacterial cell lysates by short (<20 bp) double stranded (ds) DNAs, further enrichment of YedK was observed when single stranded (ss) DNA was added. YedK can bind multiple DNA substrates, particularly with a high affinity to DNA duplex with single strand segment. As a SRAP protein, the involvement of YedK in SOS response was extensively examined, howeveryedKmutant ofEscherichia colishowed no difference from the wild type strain upon the treatments with UV and various DNA damaging reagents, indicating its non-essentiality or redundancy inE. coli. Surprisingly,yedKmutants derived fromEscherichia coliandSamonella entericaboth showed an increased plasmid DNA transformation efficiency compared to the wild types. In accordance with this, induction of YedK effectively decreased the copy number of plasmid DNA. Site-directed mutagenesis of YedK demonstrated that residues involved in single strand DNA binding and cysteine residue at position 2 from N-terminus can discharge the repression of the plasmid transformation efficiency.