Charged Amino Acids Contribute to ZorO Toxicity.
Charged Amino Acids Contribute to ZorO Toxicity.
复制标题
DOI：
10.3390/toxins15010032
复制
发表时间：
2022-12-31
期刊：
影响因子：
4.2
通讯作者：
Fozo EM
中科院分区：
文献类型：
--
作者：
Bogati B;Shore SFH;Nipper TD;Stoiculescu O;Fozo EM
在过去的二十年里，染色体编码的毒素-抗毒素系统在细菌物种中的鉴定和特征越来越多。毒素基因的过量产生导致产生毒素的细胞生长停滞或死亡，但其抗毒素的共表达可以抑制毒性作用。对于I型毒素-抗毒素系统的亚类，许多描述的毒素基因编码小的疏水蛋白，其具有分布在毒性蛋白序列上的几个带电残基。虽然这些带电残基被假设为对蛋白质的毒性作用至关重要，但它们尚未在不同的I型毒素中进行广泛研究。在此，我们突变的密码子编码带电残基的I型毒素zorO，从zor-orz毒素抗毒素系统，以确定其对生长抑制，膜去极化，ATP耗竭，和本地化的这种小蛋白。ZorO的无毒变体在膜和细胞质中积累，表明仅膜定位不足以产生其毒性。虽然带电残基的突变可能导致毒性改变，但这不仅取决于蛋白质内氨基酸的位置，还取决于其转化的残基，这表明带电残基在ZorO介导的毒性中的复杂作用。以前的研究表明，额外的拷贝的zor-orz系统改善生长的氨基糖苷类：内，我们注意到，这种改善的增长是独立的ZorO毒性。通过增加与FLAG标签融合的zorO基因的拷贝数，我们能够检测到从其天然启动子元件表达的蛋白质：这是未来毒素表达和功能研究的重要一步。
Chromosomally encoded toxin-antitoxin systems have been increasingly identified and characterized across bacterial species over the past two decades. Overproduction of the toxin gene results in cell growth stasis or death for the producing cell, but co-expression of its antitoxin can repress the toxic effects. For the subcategory of type I toxin-antitoxin systems, many of the described toxin genes encode a small, hydrophobic protein with several charged residues distributed across the sequence of the toxic protein. Though these charged residues are hypothesized to be critical for the toxic effects of the protein, they have not been studied broadly across different type I toxins. Herein, we mutated codons encoding charged residues in the type I toxin zorO, from the zor-orz toxin-antitoxin system, to determine their impacts on growth inhibition, membrane depolarization, ATP depletion, and the localization of this small protein. The non-toxic variants of ZorO accumulated both in the membrane and cytoplasm, indicating that membrane localization alone is not sufficient for its toxicity. While mutation of a charged residue could result in altered toxicity, this was dependent not only on the position of the amino acid within the protein but also on the residue to which it was converted, suggesting a complex role of charged residues in ZorO-mediated toxicity. A previous study indicated that additional copies of the zor-orz system improved growth in aminoglycosides: within, we note that this improved growth is independent of ZorO toxicity. By increasing the copy number of the zorO gene fused with a FLAG-tag, we were able to detect the protein expressed from its native promoter elements: an important step for future studies of toxin expression and function.
登录
查看更多内容
影响因子：
4.2
作者：
Nonin-Lecomte S;Fermon L;Felden B;Pinel-Marie ML
通讯作者：
Pinel-Marie ML
影响因子：
14.8
作者：
Kelley LA;Mezulis S;Yates CM;Wass MN;Sternberg MJ
通讯作者：
Sternberg MJ
影响因子：
14.9
作者：
Fozo EM;Makarova KS;Shabalina SA;Yutin N;Koonin EV;Storz G
通讯作者：
Storz G
影响因子：
3.6
作者：
Berghoff, Bork A.;Hoekzema, Mirthe;Wagner, E. Gerhart H.
通讯作者：
Wagner, E. Gerhart H.
影响因子：
3.2
作者：
Hemm, Matthew R.;Paul, Brian J.;Storz, Gisela
通讯作者：
Storz, Gisela