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Structural determinants of autoproteolysis of the Haemophilus influenzae Hap autotransporter.

Publication ,  Journal Article
Kenjale, R; Meng, G; Fink, DL; Juehne, T; Ohashi, T; Erickson, HP; Waksman, G; St Geme, JW
Published in: Infect Immun
November 2009

Haemophilus influenzae is a gram-negative bacterium that initiates infection by colonizing the upper respiratory tract. The H. influenzae Hap autotransporter protein mediates adherence, invasion, and microcolony formation in assays with respiratory epithelial cells and presumably facilitates colonization. The serine protease activity of Hap is associated with autoproteolytic cleavage and extracellular release of the HapS passenger domain, leaving the Hapbeta C-terminal domain embedded in the outer membrane. Cleavage occurs most efficiently at the LN1036-37 peptide bond and to a lesser extent at three other sites. In this study, we utilized site-directed mutagenesis, homology modeling, and assays with a peptide library to characterize the structural determinants of Hap proteolytic activity and cleavage specificity. In addition, we used homology modeling to predict the S1, S2, and S4 subsite residues of the Hap substrate groove. Our results indicate that the P1 and P2 positions at the Hap cleavage sites are critical for cleavage, with leucine preferred over larger hydrophobic residues or other amino acids in these positions. The substrate groove is formed by L263 and N274 at the S1 subsite, R264 at the S2 subsite, and E265 at the S4 subsite. This information may facilitate design of approaches to block Hap activity and interfere with H. influenzae colonization.

Duke Scholars

Published In

Infect Immun

DOI

EISSN

1098-5522

Publication Date

November 2009

Volume

77

Issue

11

Start / End Page

4704 / 4713

Location

United States

Related Subject Headings

  • Serine Endopeptidases
  • Sequence Homology, Amino Acid
  • Protein Structure, Quaternary
  • Mutagenesis, Site-Directed
  • Molecular Sequence Data
  • Microbiology
  • Haemophilus influenzae
  • Blotting, Western
  • Bacterial Outer Membrane Proteins
  • Amino Acid Sequence
 

Citation

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MLA
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Kenjale, R., Meng, G., Fink, D. L., Juehne, T., Ohashi, T., Erickson, H. P., … St Geme, J. W. (2009). Structural determinants of autoproteolysis of the Haemophilus influenzae Hap autotransporter. Infect Immun, 77(11), 4704–4713. https://doi.org/10.1128/IAI.00598-09
Kenjale, Roma, Guoyu Meng, Doran L. Fink, Twyla Juehne, Tomoo Ohashi, Harold P. Erickson, Gabriel Waksman, and Joseph W. St Geme. “Structural determinants of autoproteolysis of the Haemophilus influenzae Hap autotransporter.Infect Immun 77, no. 11 (November 2009): 4704–13. https://doi.org/10.1128/IAI.00598-09.
Kenjale R, Meng G, Fink DL, Juehne T, Ohashi T, Erickson HP, et al. Structural determinants of autoproteolysis of the Haemophilus influenzae Hap autotransporter. Infect Immun. 2009 Nov;77(11):4704–13.
Kenjale, Roma, et al. “Structural determinants of autoproteolysis of the Haemophilus influenzae Hap autotransporter.Infect Immun, vol. 77, no. 11, Nov. 2009, pp. 4704–13. Pubmed, doi:10.1128/IAI.00598-09.
Kenjale R, Meng G, Fink DL, Juehne T, Ohashi T, Erickson HP, Waksman G, St Geme JW. Structural determinants of autoproteolysis of the Haemophilus influenzae Hap autotransporter. Infect Immun. 2009 Nov;77(11):4704–4713.

Published In

Infect Immun

DOI

EISSN

1098-5522

Publication Date

November 2009

Volume

77

Issue

11

Start / End Page

4704 / 4713

Location

United States

Related Subject Headings

  • Serine Endopeptidases
  • Sequence Homology, Amino Acid
  • Protein Structure, Quaternary
  • Mutagenesis, Site-Directed
  • Molecular Sequence Data
  • Microbiology
  • Haemophilus influenzae
  • Blotting, Western
  • Bacterial Outer Membrane Proteins
  • Amino Acid Sequence