Toxin-antitoxin loci are highly abundant in free-living but lost from host-associated prokaryotes.
Toxin-antitoxin loci are highly abundant in free-living but lost from host-associated prokaryotes.
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DOI：
10.1093/nar/gki201
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发表时间：
2005
影响因子：
14.9
通讯作者：
Gerdes K
中科院分区：
文献类型：
--
作者：
Pandey DP;Gerdes K
原核染色体编码毒素-抗毒素（TA）位点，通常有多个拷贝。在大肠杆菌中，实验证据表明TA基因座是应激反应元件，帮助细胞在不利的生长条件下生存。TA操纵子中的第一个基因编码一种抗毒素，该抗毒素与第二个基因编码的调节“毒素”结合并中和。RelE和MazF毒素是翻译的调节因子，可切割mRNA并与tmRNA相互作用，在基因表达的质量控制中起作用。在这里，我们展示了从126个完全测序的原核生物基因组（16个古细菌和110个细菌）中详尽搜索TA位点的结果。我们鉴定出671个TA位点，属于7个已知的TA基因家族。令人惊讶的是，专性细胞内生物缺乏TA位点，而自由生长的原核生物却特别多（结核分枝杆菌38个，欧洲亚硝基单胞菌43个）。在许多情况下，TA位点聚集并与移动遗传元件紧密相连。在最极端的情况下，霍乱弧菌的所有13个TA位点都是位于霍乱弧菌巨型整合子中的真正整合子元件。这些观察结果有力地表明，TA基因座是可移动的磁带，在染色体内部和染色体之间频繁移动，也支持了TA基因座作为有利于自由生活的原核生物的应激反应元件的假设。
Prokaryotic chromosomes code for toxin–antitoxin (TA) loci, often in multiple copies. In E.coli, experimental evidence indicates that TA loci are stress-response elements that help cells survive unfavorable growth conditions. The first gene in a TA operon codes for an antitoxin that combines with and neutralizes a regulatory ‘toxin’, encoded by the second gene. RelE and MazF toxins are regulators of translation that cleave mRNA and function, in interplay with tmRNA, in quality control of gene expression. Here, we present the results from an exhaustive search for TA loci in 126 completely sequenced prokaryotic genomes (16 archaea and 110 bacteria). We identified 671 TA loci belonging to the seven known TA gene families. Surprisingly, obligate intracellular organisms were devoid of TA loci, whereas free-living slowly growing prokaryotes had particularly many (38 in Mycobacterium tuberculosis and 43 in Nitrosomonas europaea). In many cases, TA loci were clustered and closely linked to mobile genetic elements. In the most extreme of these cases, all 13 TA loci of Vibrio cholerae were bona fide integron elements located in the V.cholerae mega-integron. These observations strongly suggest that TA loci are mobile cassettes that move frequently within and between chromosomes and also lend support to the hypothesis that TA loci function as stress-response elements beneficial to free-living prokaryotes.
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影响因子：
3.6
作者：
HALL, RM;BROOKES, DE;STOKES, HW
通讯作者：
STOKES, HW
影响因子：
5.6
作者：
Gronlund, H;Gerdes, K
通讯作者：
Gerdes, K
影响因子：
3.2
作者：
KULAKAUSKAS, S;LUBYS, A;EHRLICH, SD
通讯作者：
EHRLICH, SD
DOI：
10.1073/pnas.251327898
发表时间：
2001-12-04
影响因子：
11.1
作者：
Christensen, SK;Mikkelsen, M;Gerdes, K
通讯作者：
Gerdes, K
影响因子：
5.6
作者：
LEHNHERR, H;MAGUIN, E;YARMOLINSKY, MB
通讯作者：
YARMOLINSKY, MB