%0 Journal Article
%A Lunelli, Michele
%A Kamprad, Antje
%A Bürger, Jörg
%A Mielke, Thorsten
%A Spahn, Christian M. T.
%A Kolbe, Michael
%T Cryo-EM structure of the Shigella type III needle complex
%J PLoS pathogens
%V 16
%N 2
%@ 1553-7366
%C Lawrence, Kan.
%I PLoS
%M PUBDB-2024-00591
%P e1008263 
%D 2020
%X The Type III Secretion Systems (T3SS) needle complex is a conserved syringe-shaped protein translocation nanomachine with a mass of about 3.5 MDa essential for the survival and virulence of many Gram-negative bacterial pathogens. This system is composed of a membrane-embedded basal body and an extracellular needle that deliver effector proteins into host cells. High-resolution structures of the T3SS from different organisms and infection stages are needed to understand the underlying molecular mechanisms of effector translocation. Here, we present the cryo-electron microscopy structure of the isolated Shigella T3SS needle complex. The inner membrane (IM) region of the basal body adopts 24-fold rotational symmetry and forms a channel system that connects the bacterial periplasm with the export apparatus cage. The secretin oligomer adopts a heterogeneous architecture with 16- and 15-fold cyclic symmetry in the periplasmic N-terminal connector and C-terminal outer membrane ring, respectively. Two out of three IM subunits bind the secretin connector via a β-sheet augmentation. The cryo-EM map also reveals the helical architecture of the export apparatus core, the inner rod, the needle and their intervening interfaces. 
%F PUB:(DE-HGF)16
%9 Journal Article
%$ pmid:32092125
%U <Go to ISI:>//WOS:000518637800012
%R 10.1371/journal.ppat.1008263
%U https://bib-pubdb1.desy.de/record/602316