Glutamine-rich toxic proteins GrtA, GrtB and GrtC together with the antisense RNA AsgR constitute a toxin-antitoxin-like system in Corynebacterium glutamicum.
Glutamine-rich toxic proteins GrtA, GrtB and GrtC together with the antisense RNA AsgR constitute a toxin-antitoxin-like system in Corynebacterium glutamicum.
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谷氨酸棒杆菌中富含谷氨酰胺的有毒蛋白GrtA、GrtB和GrtC与反义RNA AsgR一起构成了毒素-抗毒素样系统。
DOI：
10.1111/mmi.13951
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Inui M.
中科院分区：
文献类型：
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作者：
Maeda T;Tanaka Y;Inui M.
谷氨酸棒杆菌RgrtA（cgR_2936）、grtB（cgR_2934）和grtC（cgR_2933）基因被鉴定为编码富含谷氨酰胺有毒蛋白的旁系同源物。我们还鉴定了一个新的反义小RNA AsgR（反义sRNA forgrtA），它与grtA基因的3'端重叠。 grtA、grtB和grt的单次过表达导致大肠杆菌细胞生长的完全抑制。 AsgR 的共表达挽救了这种生长。在 C 中观察到类似的效果。谷氨酸，尽管这些蛋白质的毒性中等。 AsgR 转录的抑制导致 grtA、grtB 和 grtC mRNA 水平增加并延长半衰期。我们还发现在RNase III缺失突变体中grtA、grtBandgrtC的表达水平增加。引物延伸分析显示 RNase III 切割位点位于 grtAmRNA 的 3' 非翻译区 (3'-UTR)。 grtA、grtB和grtC的表达水平在受到多种胁迫后增加，包括热休克、青霉素G、溶菌酶或H2O2处理。 grtABC和sgR基因的缺失导致在几种胁迫下存活率下降。这些结果表明GrtABC和AsgR在C中构成了I型毒素-抗毒素样系统。谷氨酸。
TheCorynebacterium glutamicumRgrtA(cgR_2936),grtB(cgR_2934) andgrtC(cgR_2933) genes were identified as paralogs encoding glutamine‐rich toxic proteins. We also identified a new antisense small RNA AsgR (antisense sRNA forgrtA) that overlaps the 3′ end of thegrtAgene. Single over‐expressions ofgrtA,grtBandgrtCresulted in complete inhibition ofEscherichia colicell growth. This growth was rescued by co‐expression of AsgR. Similar effects were observed inC. glutamicum, although the toxicities of these proteins were moderate. Inhibition of AsgR transcription resulted in increased levels and prolonged half‐lives ofgrtA,grtBandgrtCmRNAs. We also found that the expression levels ofgrtA,grtBandgrtCwere increased in an RNase III deletion mutant. Primer extension analysis revealed the RNase III cleavage site to be in the 3′ untranslated region (3′‐UTR) of thegrtAmRNA. The expression levels ofgrtA,grtBandgrtCwere increased after exposure to several stresses, including heat shock, treatment with penicillin G, lysozyme or H2O2. The deletions ofgrtABCandasgRgenes resulted in decreased survival rate under several stresses. These results indicate that GrtABC and AsgR constitute a type I toxin–antitoxin‐like system inC. glutamicum.