3K8G

Structure of crystal form I of TP0453


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.254 
  • R-Value Work: 0.215 
  • R-Value Observed: 0.217 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

The Transition from Closed to Open Conformation of Treponema pallidum Outer Membrane-associated Lipoprotein TP0453 Involves Membrane Sensing and Integration by Two Amphipathic Helices.

Luthra, A.Zhu, G.Desrosiers, D.C.Eggers, C.H.Mulay, V.Anand, A.McArthur, F.A.Romano, F.B.Caimano, M.J.Heuck, A.P.Malkowski, M.G.Radolf, J.D.

(2011) J Biol Chem 286: 41656-41668

  • DOI: https://doi.org/10.1074/jbc.M111.305284
  • Primary Citation of Related Structures:  
    3K8G, 3K8H, 3K8I, 3K8J

  • PubMed Abstract: 

    The molecular architecture and composition of the outer membrane (OM) of Treponema pallidum (Tp), the noncultivable agent of venereal syphilis, differ considerably from those of typical Gram-negative bacteria. Several years ago we described TP0453, the only lipoprotein associated with the inner leaflet of the Tp OM. Whereas polypeptides of other treponemal lipoproteins are hydrophilic, non-lipidated TP0453 can integrate into membranes, a property attributed to its multiple amphipathic helices (AHs). Furthermore, membrane integration of the TP0453 polypeptide was found to increase membrane permeability, suggesting the molecule functions in a porin-like manner. To better understand the mechanism of membrane integration of TP0453 and its physiological role in Tp OM biogenesis, we solved its crystal structure and used mutagenesis to identify membrane insertion elements. The crystal structure of TP0453 consists of an α/β/α-fold and includes five stably folded AHs. In high concentrations of detergent, TP0453 transitions from a closed to open conformation by lateral movement of two groups of AHs, exposing a large hydrophobic cavity. Triton X-114 phase partitioning, liposome floatation assay, and bis-1-anilino-8-naphthalenesulfonate binding revealed that two adjacent AHs are critical for membrane sensing/integration. Using terbium-dipicolinic acid complex-loaded large unilamellar vesicles, we found that TP0453 increased efflux of fluorophore only at acidic pH. Gel filtration and cross-linking experiments demonstrated that one AH critical for membrane sensing/insertion also forms a dimeric interface. Based on structural dynamics and comparison with Mycobacterium tuberculosis lipoproteins LprG and LppX, we propose that TP0453 functions as a carrier of lipids, glycolipids, and/or derivatives during OM biogenesis.


  • Organizational Affiliation

    Department of Medicine, University of Connecticut Health Center, Farmington, Connecticut 06030.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
30kLP
A, B
262Treponema pallidumMutation(s): 0 
Gene Names: 30klpTP_0453
Membrane Entity: Yes 
UniProt
Find proteins for O67998 (Treponema pallidum (strain Nichols))
Explore O67998 
Go to UniProtKB:  O67998
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupO67998
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.254 
  • R-Value Work: 0.215 
  • R-Value Observed: 0.217 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 87.747α = 90
b = 159.872β = 90
c = 44.527γ = 90
Software Package:
Software NamePurpose
ADSCdata collection
PHASERphasing
REFMACrefinement
DENZOdata reduction
HKL-2000data scaling

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2010-10-27
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2011-12-14
    Changes: Database references
  • Version 1.3: 2023-09-06
    Changes: Data collection, Database references, Derived calculations, Refinement description