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Haemophilus influenzae surface fibril (Hsf) is a unique twisted hairpin-like trimeric autotransporter.

Singh, Birendra LU ; Tamim, Al-Jubair LU ; Mörgelin, Matthias LU ; Sundin, Anders; Linse, Sara; Nilsson, Ulf J and Riesbeck, Kristian LU (2015) In International Journal of Medical Microbiology 305(1). p.27-37
Abstract
The Haemophilus surface fibril (Hsf) is an extraordinary large (2413 amino acids) trimeric autotransporter, present in all encapsulated Haemophilus influenzae. It contributes to virulence by directly functioning as an adhesin. Furthermore, Hsf recruits the host factor vitronectin thereby inhibiting the host innate immune response resulting in enhanced survival in serum. Here we observed by electron microscopy that Hsf appears as an 100nm long fibril at the bacterial surface albeit the length is approximately 200nm according to a bioinformatics based model. To unveil this discrepancy, we denaturated Hsf at the surface of Hib by using guanidine hydrochloride (GuHCl). Partial denaturation induced in the presence of GuHCl unfolded the Hsf... (More)
The Haemophilus surface fibril (Hsf) is an extraordinary large (2413 amino acids) trimeric autotransporter, present in all encapsulated Haemophilus influenzae. It contributes to virulence by directly functioning as an adhesin. Furthermore, Hsf recruits the host factor vitronectin thereby inhibiting the host innate immune response resulting in enhanced survival in serum. Here we observed by electron microscopy that Hsf appears as an 100nm long fibril at the bacterial surface albeit the length is approximately 200nm according to a bioinformatics based model. To unveil this discrepancy, we denaturated Hsf at the surface of Hib by using guanidine hydrochloride (GuHCl). Partial denaturation induced in the presence of GuHCl unfolded the Hsf molecules, and resulted in an increased length of fibres in comparison to the native trimeric form. Importantly, our findings were also verified by E. coli expressing Hsf at its surface. In addition, a set of Hsf-specific peptide antibodies also indicated that the N-terminal of Hsf is located near the C-terminal at the base of the fibril. Taken together, our results demonstrated that Hsf is not a straight molecule but is folded and doubled over. This is the first report that provides the unique structural features of the trimeric autotransporter Hsf. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
International Journal of Medical Microbiology
volume
305
issue
1
pages
27 - 37
publisher
Elsevier
external identifiers
  • pmid:25465160
  • wos:000348957700004
  • scopus:84925746317
ISSN
1618-0607
DOI
10.1016/j.ijmm.2014.10.004
language
English
LU publication?
yes
id
f93a715d-cb14-442d-bfa8-539bfc8a8846 (old id 4912873)
alternative location
http://www.ncbi.nlm.nih.gov/pubmed/25465160?dopt=Abstract
date added to LUP
2015-01-08 19:07:48
date last changed
2017-01-01 03:53:58
@article{f93a715d-cb14-442d-bfa8-539bfc8a8846,
  abstract     = {The Haemophilus surface fibril (Hsf) is an extraordinary large (2413 amino acids) trimeric autotransporter, present in all encapsulated Haemophilus influenzae. It contributes to virulence by directly functioning as an adhesin. Furthermore, Hsf recruits the host factor vitronectin thereby inhibiting the host innate immune response resulting in enhanced survival in serum. Here we observed by electron microscopy that Hsf appears as an 100nm long fibril at the bacterial surface albeit the length is approximately 200nm according to a bioinformatics based model. To unveil this discrepancy, we denaturated Hsf at the surface of Hib by using guanidine hydrochloride (GuHCl). Partial denaturation induced in the presence of GuHCl unfolded the Hsf molecules, and resulted in an increased length of fibres in comparison to the native trimeric form. Importantly, our findings were also verified by E. coli expressing Hsf at its surface. In addition, a set of Hsf-specific peptide antibodies also indicated that the N-terminal of Hsf is located near the C-terminal at the base of the fibril. Taken together, our results demonstrated that Hsf is not a straight molecule but is folded and doubled over. This is the first report that provides the unique structural features of the trimeric autotransporter Hsf.},
  author       = {Singh, Birendra and Tamim, Al-Jubair and Mörgelin, Matthias and Sundin, Anders and Linse, Sara and Nilsson, Ulf J and Riesbeck, Kristian},
  issn         = {1618-0607},
  language     = {eng},
  number       = {1},
  pages        = {27--37},
  publisher    = {Elsevier},
  series       = {International Journal of Medical Microbiology},
  title        = {Haemophilus influenzae surface fibril (Hsf) is a unique twisted hairpin-like trimeric autotransporter.},
  url          = {http://dx.doi.org/10.1016/j.ijmm.2014.10.004},
  volume       = {305},
  year         = {2015},
}