3EH0

Crystal Structure of LpxD from Escherichia coli


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.6 Å
  • R-Value Free: 0.279 
  • R-Value Work: 0.214 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Crystal structure and acyl chain selectivity of Escherichia coli LpxD, the N-acyltransferase of lipid A biosynthesis

Bartling, C.M.Raetz, C.R.

(2009) Biochemistry 48: 8672-8683

  • DOI: 10.1021/bi901025v

  • PubMed Abstract: 
  • LpxD catalyzes the third step of lipid A biosynthesis, the R-3-hydroxyacyl-ACP-dependent N-acylation of UDP-3-O-(acyl)-alpha-D-glucosamine, and is a target for new antibiotic development. Here we report the 2.6 A crystal structure of the Escherichia ...

    LpxD catalyzes the third step of lipid A biosynthesis, the R-3-hydroxyacyl-ACP-dependent N-acylation of UDP-3-O-(acyl)-alpha-D-glucosamine, and is a target for new antibiotic development. Here we report the 2.6 A crystal structure of the Escherichia coli LpxD homotrimer (EcLpxD). As is the case in Chlamydia trachomatis LpxD (CtLxpD), each EcLpxD chain consists of an N-terminal uridine-binding region, a left-handed parallel beta-helix (LbetaH), and a C-terminal alpha-helical domain. The backbones of the LbetaH domains of the two enzymes are similar, as are the positions of key active site residues. The N-terminal nucleotide binding domains are oriented differently relative to the LbetaH regions, but are similar when overlaid on each other. The orientation of the EcLpxD tripeptide (residues 303-305), connecting the distal end of the LbetaH and the proximal end of the C-terminal helical domains, differs from its counterpart in CtLpxD (residues 311-312); this results in a 120 degrees rotation of the C-terminal domain relative to the LbetaH region in EcLpxD versus CtLpxD. M290 of EcLpxD appears to cap the distal end of a hydrophobic cleft that binds the acyl chain of the R-3-hydroxyacyl-ACP donor substrate. Under standard assay conditions, wild-type EcLpxD prefers R,S-3-hydroxymyristoyl-ACP over R,S-3-hydroxypalmitoyl-ACP by a factor of 3, whereas the M290A mutant has the opposite selectivity. Both wild-type and M290A EcLpxD rescue the conditional lethality of E. coli RL25, a temperature-sensitive strain harboring point mutations in lpxD. Complementation with wild-type EcLpxD restores normal lipid A containing only N-linked hydroxymyristate to RL25 at 42 degrees C, as judged by mass spectrometry, whereas the M290A mutant generates multiple lipid A species containing one or two longer hydroxy fatty acids in place of the usual R-3-hydroxymyristate at positions 2 and 2'.


    Organizational Affiliation

    Department of Biochemistry, Duke University Medical Center, Durham, North Carolina 27710, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
UDP-3-O-[3-hydroxymyristoyl] glucosamine N-acyltransferase
A, B, C
341Escherichia coli (strain K12)Mutation(s): 1 
Gene Names: lpxD (firA, omsA)
EC: 2.3.1.191
Find proteins for P21645 (Escherichia coli (strain K12))
Go to UniProtKB:  P21645
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.6 Å
  • R-Value Free: 0.279 
  • R-Value Work: 0.214 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 157.950α = 90.00
b = 94.170β = 126.50
c = 103.660γ = 90.00
Software Package:
Software NamePurpose
REFMACrefinement
XDSdata scaling
HKL-2000data collection
XDSdata reduction
PHASERphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2009-08-18
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance