2R19

Crystal structure of the periplasmic lipopolysaccharide transport protein LptA (YhbN), orthorhombic form

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.16 Å
  • R-Value Free: 0.271 
  • R-Value Work: 0.217 
  • R-Value Observed: 0.219 

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This is version 1.2 of the entry. See complete history. 


Literature

Novel structure of the conserved gram-negative lipopolysaccharide transport protein A and mutagenesis analysis.

Suits, M.D., Sperandeo, P., Deho, G., Polissi, A., Jia, Z.

(2008) J Mol Biol 380: 476-488

  • DOI: 10.1016/j.jmb.2008.04.045
  • Primary Citation of Related Structures:  
    2R19, 2R1A

  • PubMed Abstract: 

    • Lipopolysaccharide (LPS) transport protein A (LptA) is an essential periplasmic localized transport protein that has been implicated together with MsbA, LptB, and the Imp/RlpB complex in LPS transport from the inner membrane to the outer membrane, thereby contributing to building the cell envelope in Gram-negative bacteria and maintaining its integrity ...

    Lipopolysaccharide (LPS) transport protein A (LptA) is an essential periplasmic localized transport protein that has been implicated together with MsbA, LptB, and the Imp/RlpB complex in LPS transport from the inner membrane to the outer membrane, thereby contributing to building the cell envelope in Gram-negative bacteria and maintaining its integrity. Here we present the first crystal structures of processed Escherichia coli LptA in two crystal forms, one with two molecules in the asymmetric unit and the other with eight. In both crystal forms, severe anisotropic diffraction was corrected, which facilitated model building and structural refinement. The eight-molecule form of LptA is induced when LPS or Ra-LPS (a rough chemotype of LPS) is included during crystallization. The unique LptA structure represents a novel fold, consisting of 16 consecutive antiparallel beta-strands, folded to resemble a slightly twisted beta-jellyroll. Each LptA molecule interacts with an adjacent LptA molecule in a head-to-tail fashion to resemble long fibers. Site-directed mutagenesis of conserved residues located within a cluster that delineate the N-terminal beta-strands of LptA does not impair the function of the protein, although their overexpression appears more detrimental to LPS transport compared with wild-type LptA. Moreover, altered expression of both wild-type and mutated proteins interfered with normal LPS transport as witnessed by the production of an anomalous form of LPS. Structural analysis suggests that head-to-tail stacking of LptA molecules could be destabilized by the mutation, thereby potentially contributing to impair LPS transport.

    Organizational Affiliation: 

    Department of Biochemistry, Queen's University, Kingston, Ontario, Canada.



Macromolecules
Find similar proteins by: 
(by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Protein yhbNA, B159Escherichia coli K-12Mutation(s): 0 
Gene Names: yhbN, b3200, JW3167, lptA
UniProt
Find proteins for P0ADV1 (Escherichia coli (strain K12))
Explore P0ADV1 
Go to UniProtKB:  P0ADV1
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP0ADV1
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.16 Å
  • R-Value Free: 0.271 
  • R-Value Work: 0.217 
  • R-Value Observed: 0.219 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 47.91α = 90
b = 58.41β = 90
c = 149.62γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
SHARPphasing
DMphasing
REFMACrefinement
PDB_EXTRACTdata extraction
HKL-2000data collection
HKL-2000data reduction

Structure Validation

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View more in-depth experimental data

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2008-04-29
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Source and taxonomy, Version format compliance
  • Version 1.2: 2017-10-25
    Changes: Refinement description