Crystal Structure of ATPase delta1-79 Spa47 E287RCrystal Structure of ATPase delta1-79 Spa47 E287R

Structural highlights

6n76 is a 2 chain structure with sequence from Shigella flexneri. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 2.892Å
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

SCTN_SHIFL ATPase component of the type III secretion system (T3SS), also called injectisome, which is used to inject bacterial effector proteins into eukaryotic host cells (PubMed:26947936, PubMed:27770024, PubMed:29595954). Acts as a molecular motor to provide the energy that is required for the export of proteins (Probable). Required for type III secretion apparatus (T3SA) formation, proper protein secretion, host cell invasion and virulence (PubMed:26947936, PubMed:27770024, PubMed:31162724). May play a critical role in T3SS substrate recognition, disassembly of the effector/chaperone complex and unfolding of the effector in an ATP-dependent manner prior to secretion (By similarity).[UniProtKB:P0A1B9][1] [2] [3] [4] [5] [6]

Publication Abstract from PubMed

Like many Gram-negative pathogens, Shigella rely on a type three secretion system (T3SS) for injection of effector proteins directly into eukaryotic host cells to initiate and sustain infection. Protein secretion through the needle-like type three secretion apparatus (T3SA) requires ATP hydrolysis by the T3SS ATPase Spa47, making it a likely target for in vivo regulation of T3SS activity and an attractive target for small molecule therapeutics against shigellosis. Here, we developed a model of an activated Spa47 homo-hexamer, identifying two distinct regions at each protomer interface that we hypothesized to provide intermolecular interactions supporting Spa47 oligomerization and enzymatic activation. Mutational analysis and a series of high-resolution crystal structures confirm the importance of these residues, as many of the engineered mutants are unable to form oligomers and efficiently hydrolyze ATP in vitro. Furthermore, in vivo evaluation of Shigella virulence phenotype uncovered a strong correlation between T3SS effector protein secretion, host cell membrane disruption, and cellular invasion by the tested mutant strains, suggesting that perturbation of the identified interfacial residues/interactions influences Spa47 activity through preventing oligomer formation, which in turn regulates Shigella virulence. The most impactful mutations are observed within the conserved Site 2 interface where the native residues support oligomerization and likely contribute to a complex hydrogen bonding network that organizes the active site and supports catalysis. The critical reliance on these conserved residues suggests that aspects of T3SS regulation may also be conserved, providing promise for the development of a cross-species therapeutic that broadly targets T3SS ATPase oligomerization and activation.

Interfacial amino acids support Spa47 oligomerization and shigella type three secretion system activation.,Demler HJ, Case HB, Morales Y, Bernard AR, Johnson SJ, Dickenson NE Proteins. 2019 Jun 4. doi: 10.1002/prot.25754. PMID:31162724[7]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

See Also

References

  1. Burgess JL, Jones HB, Kumar P, Toth RT 4th, Middaugh CR, Antony E, Dickenson NE. Spa47 is an oligomerization-activated type three secretion system (T3SS) ATPase from Shigella flexneri. Protein Sci. 2016 May;25(5):1037-48. PMID:26947936 doi:10.1002/pro.2917
  2. Burgess JL, Burgess RA, Morales Y, Bouvang JM, Johnson SJ, Dickenson NE. Structural and Biochemical Characterization of Spa47 Provides Mechanistic Insight into Type III Secretion System ATPase Activation and Shigella Virulence Regulation. J Biol Chem. 2016 Oct 21. pii: jbc.M116.755256. PMID:27770024 doi:http://dx.doi.org/10.1074/jbc.M116.755256
  3. Case HB, Dickenson NE. MxiN Differentially Regulates Monomeric and Oligomeric Species of the Shigella Type Three Secretion System ATPase Spa47. Biochemistry. 2018 Apr 17;57(15):2266-2277. PMID:29595954 doi:10.1021/acs.biochem.8b00070
  4. Demler HJ, Case HB, Morales Y, Bernard AR, Johnson SJ, Dickenson NE. Interfacial amino acids support Spa47 oligomerization and shigella type three secretion system activation. Proteins. 2019 Jun 4. doi: 10.1002/prot.25754. PMID:31162724 doi:http://dx.doi.org/10.1002/prot.25754
  5. Burgess JL, Jones HB, Kumar P, Toth RT 4th, Middaugh CR, Antony E, Dickenson NE. Spa47 is an oligomerization-activated type three secretion system (T3SS) ATPase from Shigella flexneri. Protein Sci. 2016 May;25(5):1037-48. PMID:26947936 doi:10.1002/pro.2917
  6. Burgess JL, Burgess RA, Morales Y, Bouvang JM, Johnson SJ, Dickenson NE. Structural and Biochemical Characterization of Spa47 Provides Mechanistic Insight into Type III Secretion System ATPase Activation and Shigella Virulence Regulation. J Biol Chem. 2016 Oct 21. pii: jbc.M116.755256. PMID:27770024 doi:http://dx.doi.org/10.1074/jbc.M116.755256
  7. Demler HJ, Case HB, Morales Y, Bernard AR, Johnson SJ, Dickenson NE. Interfacial amino acids support Spa47 oligomerization and shigella type three secretion system activation. Proteins. 2019 Jun 4. doi: 10.1002/prot.25754. PMID:31162724 doi:http://dx.doi.org/10.1002/prot.25754

6n76, resolution 2.89Å

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