Cryo-EM structure of the bifunctional secretin complex of Thermus thermophilus

D’Imprima, Edoardo; Salzer, Ralph; Bhaskara, Ramachandra M; Sánchez, Raydel Martínez; Rose, Ilona; Kirchner, Lennart; Hummer, Gerhard; Kühlbrandt, Werner; Vonck, Janet; Averhoff, Beate

doi:10.7554/elife.30483

Cited by 32 publications

(27 citation statements)

References 64 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The structure of various T4P secretins has been examined [38][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54] , including structures of PilQ from Neisseria meningitidis 45 , Pseudomonas aeruginosa 46 , and Thermus thermophilus 47 , although no work has provided high-resolution details sufficient to model the passage of DNA or to design inhibitors of this potential drug target. Thus, structural information about the T4P secretins has mainly been inferred from the related but distinct T2SS and T3SS secretins [55][56][57][58][59][60][61] .…”

mentioning

confidence: 99%

CryoEM structure of the type IVa pilus secretin required for natural competence in Vibrio cholerae

et al. 2020

View full text Add to dashboard Cite

Natural transformation is the process by which bacteria take up genetic material from their environment and integrate it into their genome by homologous recombination. It represents one mode of horizontal gene transfer and contributes to the spread of traits like antibiotic resistance. In Vibrio cholerae, a type IVa pilus (T4aP) is thought to facilitate natural transformation by extending from the cell surface, binding to exogenous DNA, and retracting to thread this DNA through the outer membrane secretin, PilQ. Here, we use a functional tagged allele of VcPilQ purified from native V. cholerae cells to determine the cryoEM structure of the VcPilQ secretin in amphipol to ~2.7 Å. We use bioinformatics to examine the domain architecture and gene neighborhood of T4aP secretins in Proteobacteria in comparison with VcPilQ. This structure highlights differences in the architecture of the T4aP secretin from the type II and type III secretion system secretins. Based on our cryoEM structure, we design a series of mutants to reversibly regulate VcPilQ gate dynamics. These experiments support the idea of VcPilQ as a potential druggable target and provide insight into the channel that DNA likely traverses to promote the spread of antibiotic resistance via horizontal gene transfer by natural transformation.

show abstract

mentioning

confidence: 99%

CryoEM structure of the type IVa pilus secretin required for natural competence in Vibrio cholerae

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Two retraction ATPases, PilT1 and PilT2, are essential for T4P depolymerisation 8,9 . T4P are extruded through the outer membrane secretin PilQ [10][11][12][13] . Recently, it has been suggested that expression of the T. thermophilus major pilin PilA4 is temperature dependent, leading to hyperpiliation at suboptimal growth temperatures 14 .…”

mentioning

confidence: 99%

Cryo-electron microscopy reveals two distinct type IV pili assembled by the same bacterium

et al. 2020

Self Cite

View full text Add to dashboard Cite

Type IV pili are flexible filaments on the surface of bacteria, consisting of a helical assembly of pilin proteins. They are involved in bacterial motility (twitching), surface adhesion, biofilm formation and DNA uptake (natural transformation). Here, we use cryo-electron microscopy and mass spectrometry to show that the bacterium Thermus thermophilus produces two forms of type IV pilus ('wide' and 'narrow'), differing in structure and protein composition. Wide pili are composed of the major pilin PilA4, while narrow pili are composed of a so-far uncharacterized pilin which we name PilA5. Functional experiments indicate that PilA4 is required for natural transformation, while PilA5 is important for twitching motility.

show abstract

“…N0 in EpsD from the T2SS of V. vulnificus was not traceable in the cryo‐EM map due to flexibility and is thus indicated in blue. Numbers indicate domain delimitations, as indicated in the publications describing the structures in Figure …”

Section: Introductionmentioning

confidence: 99%

Bacterial secretins: Mechanisms of assembly and membrane targeting

et al. 2020

View full text Add to dashboard Cite

Secretion systems are employed by bacteria to transport macromolecules across membranes without compromising their integrities. Processes including virulence, colonization, and motility are highly dependent on the secretion of effector molecules toward the immediate cellular environment, and in some cases, into the host cytoplasm. In Type II and Type III secretion systems, as well as in Type IV pili, homomultimeric complexes known as secretins form large pores in the outer bacterial membrane, and the localization and assembly of such 1 MDa molecules often relies on pilotins or accessory proteins. Significant progress has been made toward understanding details of interactions between secretins and their partner proteins using approaches ranging from bacterial genetics to cryo electron microscopy. This review provides an overview of the mode of action of pilotins and accessory proteins for T2SS, T3SS, and T4PS secretins, highlighting recent near‐atomic resolution cryo‐EM secretin complex structures and underlining the importance of these interactions for secretin functionality.

show abstract

Cryo-EM structure of the bifunctional secretin complex of Thermus thermophilus

Cited by 32 publications

References 64 publications

CryoEM structure of the type IVa pilus secretin required for natural competence in Vibrio cholerae

CryoEM structure of the type IVa pilus secretin required for natural competence in Vibrio cholerae

Cryo-electron microscopy reveals two distinct type IV pili assembled by the same bacterium

Bacterial secretins: Mechanisms of assembly and membrane targeting

Contact Info

Product

Resources

About