气候变化领域集成服务门户(CCPortal): The β-encapsulation cage of rearrangement hotspot (Rhs) effectors is required for type VI secretion

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DOI	10.1073/PNAS.1919350117
	The β-encapsulation cage of rearrangement hotspot (Rhs) effectors is required for type VI secretion
	Donato S.L.; Beck C.M.; Garza-Sánchez F.; Jensen S.J.; Ruhe Z.C.; Cunningham D.A.; Singleton I.; Low D.A.; Hayes C.S.
发表日期	2021
ISSN	00278424
起始页码	33540
结束页码	33548
卷号	117 期号:52
英文摘要	Bacteria deploy rearrangement hotspot (Rhs) proteins as toxic effectors against both prokaryotic and eukaryotic target cells. Rhs proteins are characterized by YD-peptide repeats, which fold into a large β-cage structure that encapsulates the C-terminal toxin domain. Here, we show that Rhs effectors are essential for type VI secretion system (T6SS) activity in Enterobacter cloacae (ECL). ECL rhs− mutants do not kill Escherichia coli target bacteria and are defective for T6SS-dependent export of hemolysin-coregulated protein (Hcp). The RhsA and RhsB effectors of ECL both contain Pro−Ala−Ala−Arg (PAAR) repeat domains, which bind the β-spike of trimeric valine−glycine repeat protein G (VgrG) and are important for T6SS activity in other bacteria. Truncated RhsA that retains the PAAR domain is capable of forming higher-order, thermostable complexes with VgrG, yet these assemblies fail to restore secretion activity to ΔrhsA ΔrhsB mutants. Full T6SS-1 activity requires Rhs that contains N-terminal transmembrane helices, the PAAR domain, and an intact β-cage. Although ΔrhsA ΔrhsB mutants do not kill target bacteria, time-lapse microscopy reveals that they assemble and fire T6SS contractile sheaths at ∼6% of the frequency of rhs+ cells. Therefore, Rhs proteins are not strictly required for T6SS assembly, although they greatly increase secretion efficiency. We propose that PAAR and the β-cage provide distinct structures that promote secretion. PAAR is clearly sufficient to stabilize trimeric VgrG, but efficient assembly of T6SS-1 also depends on an intact β-cage. Together, these domains enforce a quality control checkpoint to ensure that VgrG is loaded with toxic cargo before assembling the secretion apparatus. © 2020 National Academy of Sciences. All rights reserved.
英文关键词	Bacterial competition; Self/nonself discrimination; Toxin-immunity proteins
语种	英语
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/179600
作者单位	Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA 93106-9625, United States; Biomolecular Science and Engineering Program, University of California, Santa Barbara, CA 93106-9625, United States; Department of Surgery, University of Washington School of Medicine, Seattle, WA 98195, United States
推荐引用方式 GB/T 7714	Donato S.L.,Beck C.M.,Garza-Sánchez F.,et al. The β-encapsulation cage of rearrangement hotspot (Rhs) effectors is required for type VI secretion[J],2021,117(52).
APA	Donato S.L..,Beck C.M..,Garza-Sánchez F..,Jensen S.J..,Ruhe Z.C..,...&Hayes C.S..(2021).The β-encapsulation cage of rearrangement hotspot (Rhs) effectors is required for type VI secretion.Proceedings of the National Academy of Sciences of the United States of America,117(52).
MLA	Donato S.L.,et al."The β-encapsulation cage of rearrangement hotspot (Rhs) effectors is required for type VI secretion".Proceedings of the National Academy of Sciences of the United States of America 117.52(2021).