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The crystal structure of GXGD membrane protease FlaK

Abstract

The GXGD proteases are polytopic membrane proteins with catalytic activities against membrane-spanning substrates that require a pair of aspartyl residues1,2,3,4. Representative members of the family include preflagellin peptidase, type 4 prepilin peptidase, presenilin and signal peptide peptidase. Many GXGD proteases are important in medicine. For example, type 4 prepilin peptidase may contribute to bacterial pathogenesis5,6,7, and mutations in presenilin are associated with Alzheimer’s disease8,9,10. As yet, there is no atomic-resolution structure in this protease family. Here we report the crystal structure of FlaK, a preflagellin peptidase from Methanococcus maripaludis, solved at 3.6 Å resolution. The structure contains six transmembrane helices. The GXGD motif and a short transmembrane helix, helix 4, are positioned at the centre, surrounded by other transmembrane helices. The crystal structure indicates that the protease must undergo conformational changes to bring the GXGD motif and a second essential aspartyl residue from transmembrane helix 1 into close proximity for catalysis. A comparison of the crystal structure with models of presenilin derived from biochemical analysis reveals three common transmembrane segments that are similarly arranged around the active site. This observation reinforces the idea that the prokaryotic and human proteases are evolutionarily related11,12. The crystal structure presented here provides a framework for understanding the mechanism of the GXGD proteases, and may facilitate the rational design of inhibitors that target specific members of the family.

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Figure 1: The structure of FlaK.
Figure 2: FlaK is tilted in the membrane.
Figure 3: The uncoupling between Asp 18 and Asp 79.
Figure 4: Structural comparison between FlaK and presenilin-1.

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Accession codes

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Protein Data Bank

Data deposits

The atomic coordinates of FlaK and structure factors have been deposited in the Protein Data Bank under accession code 3S0X.

References

  1. Wolfe, M. S. et al. Two transmembrane aspartates in presenilin-1 required for presenilin endoproteolysis and γ-secretase activity. Nature 398, 513–517 (1999)

    Article  ADS  CAS  Google Scholar 

  2. LaPointe, C. F. & Taylor, R. K. The type 4 prepilin peptidases comprise a novel family of aspartic acid proteases. J. Biol. Chem. 275, 1502–1510 (2000)

    Article  CAS  Google Scholar 

  3. Weihofen, A., Binns, K., Lemberg, M. K., Ashman, K. & Martoglio, B. Identification of signal peptide peptidase, a presenilin-type aspartic protease. Science 296, 2215–2218 (2002)

    Article  ADS  CAS  Google Scholar 

  4. Bardy, S. L. & Jarrell, K. F. Cleavage of preflagellins by an aspartic acid signal peptidase is essential for flagellation in the archaeon Methanococcus voltae . Mol. Microbiol. 50, 1339–1347 (2003)

    Article  CAS  Google Scholar 

  5. Lory, S. & Strom, M. S. Structure-function relationship of type-IV prepilin peptidase of Pseudomonas aeruginosa—a review. Gene 192, 117–121 (1997)

    Article  CAS  Google Scholar 

  6. Craig, L., Pique, M. E. & Tainer, J. A. Type IV pilus structure and bacterial pathogenicity. Nature Rev. Microbiol. 2, 363–378 (2004)

    Article  CAS  Google Scholar 

  7. Sandkvist, M. Type II secretion and pathogenesis. Infect. Immun. 69, 3523–3535 (2001)

    Article  CAS  Google Scholar 

  8. Selkoe, D. J. & Wolfe, M. S. Presenilin: running with scissors in the membrane. Cell 131, 215–221 (2007)

    Article  CAS  Google Scholar 

  9. Jorissen, E. & De Strooper, B. γ-secretase and the intramembrane proteolysis of Notch. Curr. Top. Dev. Biol. 92, 201–230 (2010)

    Article  CAS  Google Scholar 

  10. Brouwers, N., Sleegers, K. & Van Broeckhoven, C. Molecular genetics of Alzheimer’s disease: an update. Ann. Med. 40, 562–583 (2008)

    Article  CAS  Google Scholar 

  11. Steiner, H. et al. Glycine 384 is required for presenilin-1 function and is conserved in bacterial polytopic aspartyl proteases. Nature Cell Biol. 2, 848–851 (2000)

    Article  CAS  Google Scholar 

  12. Rawlings, N. D., Morton, F. R., Kok, C. Y., Kong, J. & Barrett, A. J. MEROPS: the peptidase database. Nucleic Acids Res. 36, D320–D325 (2008)

    Article  CAS  Google Scholar 

  13. Francetic, O., Buddelmeijer, N., Lewenza, S., Kumamoto, C. A. & Pugsley, A. P. Signal recognition particle-dependent inner membrane targeting of the PulG Pseudopilin component of a type II secretion system. J. Bacteriol. 189, 1783–1793 (2007)

    Article  CAS  Google Scholar 

  14. Bayley, D. P. & Jarrell, K. F. Overexpression of Methanococcus voltae flagellin subunits in Escherichia coli and Pseudomonas aeruginosa: a source of archaeal preflagellin. J. Bacteriol. 181, 4146–4153 (1999)

    CAS  PubMed  PubMed Central  Google Scholar 

  15. Kalmokoff, M. L., Karnauchow, T. M. & Jarrell, K. F. Conserved N-terminal sequences in the flagellins of archaebacteria. Biochem. Biophys. Res. Commun. 167, 154–160 (1990)

    Article  CAS  Google Scholar 

  16. Bardy, S. L. & Jarrell, K. F. FlaK of the archaeon Methanococcus maripaludis possesses preflagellin peptidase activity. FEMS Microbiol. Lett. 208, 53–59 (2002)

    Article  CAS  Google Scholar 

  17. Killian, J. A. & von Heijne, G. How proteins adapt to a membrane–water interface. Trends Biochem. Sci. 25, 429–434 (2000)

    Article  CAS  Google Scholar 

  18. Wang, Y., Maegawa, S., Akiyama, Y. & Ha, Y. The role of L1 loop in the mechanism of rhomboid intramembrane protease GlpG. J. Mol. Biol. 374, 1104–1113 (2007)

    Article  CAS  Google Scholar 

  19. Bondar, A. N., del Val, C. & White, S. H. Rhomboid protease dynamics and lipid interactions. Structure 17, 395–405 (2009)

    Article  CAS  Google Scholar 

  20. Ha, Y. Structure and mechanism of intramembrane protease. Semin. Cell Dev. Biol. 20, 240–250 (2009)

    Article  CAS  Google Scholar 

  21. Tolia, A., Chavez-Gutierrez, L. & De Strooper, B. Contribution of presenilin transmembrane domains 6 and 7 to a water-containing cavity in the γ-secretase complex. J. Biol. Chem. 281, 27633–27642 (2006)

    Article  CAS  Google Scholar 

  22. Tolia, A., Horre, K. & De Strooper, B. Transmembrane domain 9 of presenilin determines the dynamic conformation of the catalytic site of γ-secretase. J. Biol. Chem. 283, 19793–19803 (2008)

    Article  CAS  Google Scholar 

  23. Laudon, H. et al. A nine-transmembrane domain topology for presenilin 1. J. Biol. Chem. 280, 35352–35360 (2005)

    Article  CAS  Google Scholar 

  24. Spasic, D. et al. Presenilin-1 maintains a nine-transmembrane topology throughout the secretory pathway. J. Biol. Chem. 281, 26569–26577 (2006)

    Article  CAS  Google Scholar 

  25. Narayanan, S., Sato, T. & Wolfe, M. S. A C-terminal region of signal peptide peptidase defines a functional domain for intramembrane aspartic protease catalysis. J. Biol. Chem. 282, 20172–20179 (2007)

    Article  CAS  Google Scholar 

  26. Sato, C., Morohashi, Y., Tomita, T. & Iwatsubo, T. Structure of the catalytic pore of γ-secretase probed by the accessibility of substituted cysteines. J. Neurosci. 26, 12081–12088 (2006)

    Article  CAS  Google Scholar 

  27. Sato, C., Takagi, S., Tomita, T. & Iwatsubo, T. The C-terminal PAL motif and transmembrane domain 9 of presenilin 1 are involved in the formation of the catalytic pore of the γ-secretase. J. Neurosci. 28, 6264–6271 (2008)

    Article  CAS  Google Scholar 

  28. Ponting, C. P. et al. Identification of a novel family of presenilin homologues. Hum. Mol. Genet. 11, 1037–1044 (2002)

    Article  CAS  Google Scholar 

  29. Davies, D. R. The structure and function of the aspartic proteinases. Annu. Rev. Biophys. Biophys. Chem. 19, 189–215 (1990)

    Article  CAS  Google Scholar 

  30. Wang, Y. & Ha, Y. Open-cap conformation of intramembrane protease GlpG. Proc. Natl Acad. Sci. USA 104, 2098–2102 (2007)

    Article  ADS  CAS  Google Scholar 

  31. Kaback, H. R. & Stadtman, E. R. Proline uptake by an isolated cytoplasmic membrane preparation of Escherichia coli . Proc. Natl Acad. Sci. USA 55, 920–927 (1966)

    Article  ADS  CAS  Google Scholar 

  32. Otwinowski, Z. & Minor, W. Processing of X-ray diffraction data collected in oscillation mode. Methods Enzymol. 276, 307–326 (1997)

    Article  CAS  Google Scholar 

  33. Wang, B. C. Resolution of phase ambiguity in macromolecular crystallography. Methods Enzymol. 115, 90–112 (1985)

    Article  CAS  Google Scholar 

  34. Pape, T. & Schneider, T. R. HKL2MAP: a graphical user interface for macromolecular phasing with SHELX programs. J. Appl. Cryst. 37, 843–844 (2004)

    Article  CAS  Google Scholar 

  35. Collaborative Computational Project, 4. The CCP4 suite: programs for protein crystallography. Acta Crystallogr. D 50, 760–763 (1994)

    Article  Google Scholar 

  36. Jones, T. A., Zou, J. Y., Cowan, S. W. & Kjeldgaard, M. Improved methods for building protein models in electron density maps and the location of errors in these models. Acta Crystallogr. A 47, 110–119 (1991)

    Article  Google Scholar 

  37. Brünger, A. T. et al. Crystallography & NMR system: A new software suite for macromolecular structure determination. Acta Crystallogr. D 54, 905–921 (1998)

    Article  Google Scholar 

  38. Winn, M. D., Murshudov, G. N. & Papiz, M. Z. Macromolecular TLS refinement in REFMAC at moderate resolutions. Methods Enzymol. 374, 300–321 (2003)

    Article  CAS  Google Scholar 

  39. Nicholls, A., Sharp, K. A. & Honig, B. Protein folding and association: insights from the interfacial and thermodynamic properties of hydrocarbons. Proteins 11, 281–296 (1991)

    Article  CAS  Google Scholar 

  40. Loo, T. W. & Clarke, D. M. Determining the dimensions of the drug-binding domain of human P-glycoprotein using thiol cross-linking compounds as molecular rulers. J. Biol. Chem. 276, 36877–36880 (2001)

    Article  CAS  Google Scholar 

  41. Green, N. S., Reisler, E. & Houk, K. N. Quantitative evaluation of the lengths of homobifunctional protein cross-linking reagents used as molecular rulers. Protein Sci. 10, 1293–1304 (2001)

    Article  CAS  Google Scholar 

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Acknowledgements

We thank A. Héroux, H. Robinson and A. Soares at NSLS, and J. Schuermann at APS NE-CAT for their help during data collection. X-ray diffraction data were measured at beamlines X25 and X29 at NSLS, and at 24-ID-C and 24-ID-E at APS. Financial support was principally from the US Department of Energy and from the National Institutes of Health. This work was supported by a New Scholar Award in Aging from the Ellison Medical Foundation (to Y.H.), a gift from the Neuroscience Education and Research Foundation (to Y.H.) and a pilot grant from Yale’s programme in Cellular Neuroscience, Neurodegeneration, and Repair (CNNR) (to Y.H.).

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Contributions

J.H. and Y.X. purified and characterized FlaK in various detergents. J.H. obtained the high-resolution crystals of FlaK. J.H., Y.X. and Y.H. solved the crystal structure. Y.H., Y.X. and J.H. wrote the paper. Y.X. and S.L. screened many constructs and performed the initial biochemical and functional characterizations.

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Correspondence to Ya Ha.

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The authors declare no competing financial interests.

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Hu, J., Xue, Y., Lee, S. et al. The crystal structure of GXGD membrane protease FlaK. Nature 475, 528–531 (2011). https://doi.org/10.1038/nature10218

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