The HsiB1C1 (TssB-TssC) complex of the pseudomonas aeruginosa Type VI secretion system forms a bacteriophage tail sheathlike structure
Author(s)
Type
Journal Article
Abstract
Protein secretion systems in Gram-negative bacteria evolved into a variety of molecular nanomachines. They are related to cell envelope complexes, which are involved in assembly of surface appendages or transport of solutes. They are classified as types, the most recent addition being the type VI secretion system (T6SS). The T6SS displays similarities to bacteriophage tail, which drives DNA injection into bacteria. The Hcp protein is related to the T4 bacteriophage tail tube protein gp19, whereas VgrG proteins structurally resemble the gp27/gp5 puncturing device of the phage. The tube and spike of the phage are pushed through the bacterial envelope upon contraction of a tail sheath composed of gp18. In Vibrio cholerae it was proposed that VipA and VipB assemble into a tail sheathlike structure. Here we confirm these previous data by showing that HsiB1 and HsiC1 of the Pseudomonas aeruginosa H1-T6SS assemble into tubules resulting from stacking of cogwheel-like structures showing predominantly 12-fold symmetry. The internal diameter of the cogwheels is ∼100 Å, which is large enough to accommodate an Hcp tube whose external diameter has been reported to be 85 Å. The N-terminal 212 residues of HsiC1 are sufficient to form a stable complex with HsiB1, but the C terminus of HsiC1 is essential for the formation of the tubelike structure. Bioinformatics analysis suggests that HsiC1 displays similarities to gp18-like proteins in its C-terminal region. In conclusion, we provide further structural and mechanistic insights into the T6SS and show that a phage sheathlike structure is likely to be a conserved element across all T6SSs.
Date Issued
2021-01-04
Date Acceptance
2021-01-01
Citation
Journal of Biological Chemistry, 2021, 288 (11), pp.7536-7548
ISSN
0021-9258
Publisher
American Society for Biochemistry and Molecular Biology
Start Page
7536
End Page
7548
Journal / Book Title
Journal of Biological Chemistry
Volume
288
Issue
11
Copyright Statement
© 2013 ASBMB. Currently published by Elsevier Inc; originally published by American Society for Biochemistry and Molecular Biology.
Under a Creative Commons license.
Under a Creative Commons license.
Sponsor
Medical Research Council (MRC)
Medical Research Council (MRC)
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000316455300010&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Grant Number
G0800171
MR/K001930/1
Subjects
Science & Technology
Life Sciences & Biomedicine
Biochemistry & Molecular Biology
PROTEIN HOMOLOGY DETECTION
ESCHERICHIA-COLI
PHAGE
GENES
MECHANISM
MACHINE
TARGETS
ICMF
DNA
Publication Status
Published
Date Publish Online
2021-01-04