Draft Genome Sequences of Two Legionella dumoffii Strains, TEX-KL and NY-23

Qin, Tian; Cui, Yu‐Jun; Cen, Zhong; Liang, Tiantian; Ren, Hao; Yang, Xinhua; Zhao, Xiaodong; Liu, Z.; Xu, Li; Li, D.; Song, Youtao; Shao, Zhujun

doi:10.1128/jb.06352-11

Cited by 12 publications

(6 citation statements)

References 17 publications

(15 reference statements)

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“…Intriguingly, DotG proteins (typically over 100 kDa) of Legionella species and a related zoonotic pathogen C. burnetii are far larger than orthologous TraO proteins (typically 50 kDa) of IncI-plasmid conjugation systems because of an extra spacer region containing penta-peptide repeats in between innerand outer-membrane interacting regions. Moreover, Legionella dumoffii strain Tex-KL (30) and Legionella drancourtii strain LLAP12 may encode split dotG genes: in addition to the spacer region, one containing an inner-membrane spanning region and the other containing an outer-membrane interacting region. These observations raise the possibility that the outer-membrane subcomplex and DotG are flexibly placed in some situations, with or without connection via the spacer region(s) of DotG.…”

Section: Discussionmentioning

confidence: 99%

Native structure of a type IV secretion system core complex essential for Legionella pathogenesis

Kubori

Koike

Bui

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

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Bacterial type IV secretion systems are evolutionarily related to conjugation systems and play a pivotal role in infection by delivering numerous virulence factors into host cells. Using transmission electron microscopy, we report the native molecular structure of the core complex of the Dot/Icm type IV secretion system encoded by Legionella pneumophila, an intracellular human pathogen. The biochemically isolated core complex, composed of at least five proteins--DotC, DotD, DotF, DotG, and DotH--has a ring-shaped structure. Intriguingly, morphologically distinct premature complexes are formed in the absence of DotG or DotF. Our data suggest that DotG forms a central channel spanning inner and outer membranes. DotF, a component dispensable for type IV secretion, plays a role in efficient embedment of DotG into the functional core complex. These results highlight a common scheme for the biogenesis of transport machinery.

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Section: Discussionmentioning

confidence: 99%

Native structure of a type IV secretion system core complex essential for Legionella pathogenesis

Kubori

Koike

Bui

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

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“…D LupA activity removes polyubiquitin linkages from its cognate IDTS, LegC3. Denaturing IPs of FLAG-V5-LegC3 expressed in HEK293T cells were analyzed by western blot and probed for ubiquitination during co-expression of V5-LupA or one of three catalytically impaired variants (see Appendix Fig S6C for (Qin et al, 2012). We observe no crossspecies rescue on the array between MavQ (L. dumoffii) and our L. pneumophila library ( Fig 6C), consistent with a divergence of the MavQ-SidP interface since these two Legionella species' last common ancestor.…”

Section: Evolutionary Implications Of Direct Effector-effector Supprementioning

confidence: 99%

Diverse mechanisms of metaeffector activity in an intracellular bacterial pathogen, Legionella pneumophila

Urbanus

Quaile

Stogios

et al. 2016

Molecular Systems Biology

117

169

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Pathogens deliver complex arsenals of translocated effector proteins to host cells during infection, but the extent to which these proteins are regulated once inside the eukaryotic cell remains poorly defined. Among all bacterial pathogens, Legionella pneumophila maintains the largest known set of translocated substrates, delivering over 300 proteins to the host cell via its Type IVB, Icm/Dot translocation system. Backed by a few notable examples of effector-effector regulation in L. pneumophila, we sought to define the extent of this phenomenon through a systematic analysis of effector-effector functional interaction. We used Saccharomyces cerevisiae, an established proxy for the eukaryotic host, to query > 108,000 pairwise genetic interactions between two compatible expression libraries of~330 L. pneumophila-translocated substrates. While capturing all known examples of effectoreffector suppression, we identify fourteen novel translocated substrates that suppress the activity of other bacterial effectors and one pair with synergistic activities. In at least nine instances, this regulation is direct-a hallmark of an emerging class of proteins called metaeffectors, or "effectors of effectors". Through detailed structural and functional analysis, we show that metaeffector activity derives from a diverse range of mechanisms, shapes evolution, and can be used to reveal important aspects of each cognate effector's function. Metaeffectors, along with other, indirect, forms of effector-effector modulation, may be a common feature of many intracellular pathogens-with unrealized potential to inform our understanding of how pathogens regulate their interactions with the host cell.

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“…The kai operon genes were missing in three of the 41 strains and six isolates had a frameshift in the operon sequence. Analyses of the genome sequences of five L. longbeachae strains (Cazalet et al, 2010;Kozak et al, 2010), one L. drancourtii strain (Moliner et al, 2010), two L. dumoffii strains (Qin et al, 2012) and one L. anisa strain (unpublished), and the genomes of L. hackeliae, L. micdadei and L. fallonii (our unpublished data) revealed that L. hackeliae contains the kai operon and that L. fallonii contains the kaiB and lpp1114 genes but no kaiC gene, whereas the entire operon is absent from the remaining five Legionella species. This heterogeneous distribution and the mutations present in the operons might point to the fact that this operon is on an evolutionary path to be lost from Legionella.…”

Section: Evolution Of the Kaib And Kaic Proteins In L Pneumophilamentioning

confidence: 99%

The Legionella pneumophila kai operon is implicated in stress response and confers fitness in competitive environments

Loza-Correa

Sahr

Rolando

et al. 2013

Environmental Microbiology

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Summary Legionella pneumophila uses aquatic protozoa as replication niche and protection from harsh environments. Although L. pneumophila is not known to have a circadian clock, it encodes homologues of the KaiBC proteins of Cyanobacteria that regulate circadian gene expression. We show that L. pneumophila kaiB, kaiC and the downstream gene lpp1114, are transcribed as a unit under the control of the stress sigma factor RpoS. KaiC and KaiB of L. pneumophila do not interact as evidenced by yeast and bacterial two-hybrid analyses. Fusion of the C-terminal residues of cyanobacterial KaiB to Legionella KaiB restores their interaction. In contrast, KaiC of L. pneumophila conserved autophosphorylation activity, but KaiB does not trigger the dephosphorylation of KaiC like in Cyanobacteria. The crystal structure of L. pneumophila KaiB suggests that it is an oxidoreductase-like protein with a typical thioredoxin fold. Indeed, mutant analyses revealed that the kai operon-encoded proteins increase fitness of L. pneumophila in competitive environments, and confer higher resistance to oxidative and sodium stress. The phylogenetic analysis indicates that L. pneumophila KaiBC resemble Synechosystis KaiC2B2 and not circadian KaiB1C1. Thus, the L. pneumophila Kai proteins do not encode a circadian clock, but enhance stress resistance and adaption to changes in the environments.

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Draft Genome Sequences of Two Legionella dumoffii Strains, TEX-KL and NY-23

Cited by 12 publications

References 17 publications

Native structure of a type IV secretion system core complex essential for Legionella pathogenesis

Native structure of a type IV secretion system core complex essential for Legionella pathogenesis

Diverse mechanisms of metaeffector activity in an intracellular bacterial pathogen, Legionella pneumophila

The Legionella pneumophila kai operon is implicated in stress response and confers fitness in competitive environments

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