Crystal structure of cytotoxin protein suilysin from Streptococcus suis

Xu, Lingfeng; Huang, Bo; Du, Hao; Zhang, Xuejun C.; Xu, Jianguo; Li, Xuemei; Rao, Zihe

doi:10.1007/s13238-010-0012-3

Cited by 74 publications

(73 citation statements)

References 34 publications

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“…Diffraction data from three-dimensional crystals of natively secreted LLO were used for structure determination by molecular replacement 30 with Perfringolysin O (PFO) 31 as a search model. Overall, the structure of LLO resembles that of the related CDCs PFO 31 , Anthrolysin O 32 , Intermedilysin 33 , Suilysin 34 and the recently published SLO 35 . LLO is an elongated, rod-like molecule with four distinct domains, referred to as D1 to D4 (Fig.…”

Section: Resultsmentioning

confidence: 66%

Crystal structure of listeriolysin O reveals molecular details of oligomerization and pore formation

et al. 2014

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Listeriolysin O (LLO) is an essential virulence factor of Listeria monocytogenes that causes listeriosis. Listeria monocytogenes owes its ability to live within cells to the pH-and temperature-dependent pore-forming activity of LLO, which is unique among cholesteroldependent cytolysins. LLO enables the bacteria to cross the phagosomal membrane and is also involved in activation of cellular processes, including the modulation of gene expression or intracellular Ca 2 þ oscillations. Neither the pore-forming mechanism nor the mechanisms triggering the signalling processes in the host cell are known in detail. Here, we report the crystal structure of LLO, in which we identified regions important for oligomerization and pore formation. Mutants were characterized by determining their haemolytic and Ca 2 þ uptake activity. We analysed the pore formation of LLO and its variants on erythrocyte ghosts by electron microscopy and show that pore formation requires precise interface interactions during toxin oligomerization on the membrane.

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Section: Resultsmentioning

confidence: 66%

Crystal structure of listeriolysin O reveals molecular details of oligomerization and pore formation

et al. 2014

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“…Furthermore, the capsule interferes with the ability of S. suis to adhere to and invade host cells, since unencapsulated mutant strains showed a much higher adherence (and invasion) capacity when analyzed with different epithelial cell lines (12,13). Many virulent S. suis strains express a cholesterol-dependent pore-forming cytolysin, suilysin (14,15), which is the main bacterial factor causing host cell damage (13,16,17). It has been suggested that suilysin plays a role in the invasion of S. suis (13,16) as well as in immunomodulation and evasion of opsonophagocytosis (18)(19)(20), but its precise role in pathogenesis remains to be resolved.…”

mentioning

confidence: 99%

Dynamic Virus-Bacterium Interactions in a Porcine Precision-Cut Lung Slice Coinfection Model: Swine Influenza Virus Paves the Way for Streptococcus suis Infection in a Two-Step Process

Meng

Nerlich³

et al. 2015

Infect Immun

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Swine influenza virus (SIV) and Streptococcus suis are common pathogens of the respiratory tract in pigs, with both being associated with pneumonia. The interactions of both pathogens and their contribution to copathogenesis are only poorly understood. In the present study, we established a porcine precision-cut lung slice (PCLS) coinfection model and analyzed the effects of a primary SIV infection on secondary infection by S. suis at different time points. We found that SIV promoted adherence, colonization, and invasion of S. suis in a two-step process. First, in the initial stages, these effects were dependent on bacterial encapsulation, as shown by selective adherence of encapsulated, but not unencapsulated, S. suis to SIV-infected cells. Second, at a later stage of infection, SIV promoted S. suis adherence and invasion of deeper tissues by damaging ciliated epithelial cells. This effect was seen with a highly virulent SIV subtype H3N2 strain but not with a low-virulence subtype H1N1 strain, and it was independent of the bacterial capsule, since an unencapsulated S. suis mutant behaved in a way similar to that of the encapsulated wildtype strain. In conclusion, the PCLS coinfection model established here revealed novel insights into the dynamic interactions between SIV and S. suis during infection of the respiratory tract. It showed that at least two different mechanisms contribute to the beneficial effects of SIV for S. suis, including capsule-mediated bacterial attachment to SIV-infected cells and capsule-independent effects involving virus-mediated damage of ciliated epithelial cells. R espiratory diseases in swine are responsible for high economic losses in the pig industry worldwide. The upper respiratory tract is a reservoir for a heterogeneous community of (potentially) pathogenic microorganisms and commensals (1). Pneumonia often represents a multifactorial disease complex caused by mixed infections with different pathogens, including viruses and bacteria. Furthermore, unfavorable environmental conditions facilitate the development of the disease (2). Thus, it is termed porcine respiratory disease complex (PRDC) (1). Often primary viral agents, such as porcine reproductive and respiratory syndrome virus, porcine circovirus type 2, and swine influenza virus (SIV), lead to damage of the mucociliary barrier and a decreased immune response, predisposing pigs to secondary infections and pneumonia by opportunistic bacterial pathogens, such as Pasteurella multocida, Mycoplasma hyopneumoniae, and Streptococcus suis (3). However, very little is known about interactions between viral and bacterial pathogens and their role in the copathogenesis of such complex diseases.SIV is an infectious agent causing respiratory disease in pig herds, and it is associated with morbidity of up to 100%. Acute symptoms are high fever, depression, tachypnea, abdominal breathing, and, infrequently, coughing (4). SIV subtypes H1N1, H1N2, and H3N2 are pervasive and cocirculating in the swine population worldwide. Subtype H1N1 viruses...

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“…LLO is a unique CDC family member, as it is only active at low pH ranges (<5-6) but is inactive at neutral pH (7) or higher [71]. L. monocytogenes is internalized into host cells by phagocytosis or a bacterially activated internalization process.…”

Section: Dual-functional Tmhs In Llo From Listeria Monocytogenesmentioning

confidence: 99%

“…The crystal structures of six CDCs in the water-soluble monomer state have been solved, which revealed that CDCs also exhibit a high degree of tertiary structural similarity [2][3][4][5][6][7]. The homology between the primary and crystal structures of the CDCs predicts that CDC family members share many similar features and a common pore-forming mechanism, although it is clear there are some variations on this theme.…”

Section: Introduction To Cdc Familymentioning

confidence: 99%