1XX1

Structural basis for ion-coordination and the catalytic mechanism of sphingomyelinases D


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.75 Å
  • R-Value Free: 0.225 
  • R-Value Work: 0.186 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Structural basis for metal ion coordination and the catalytic mechanism of sphingomyelinases d

Murakami, M.T.Fernandes-Pedrosa, M.F.Tambourgi, D.V.Arni, R.K.

(2005) J.Biol.Chem. 280: 13658-13664

  • DOI: 10.1074/jbc.M412437200
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Sphingomyelinases D (SMases D) from Loxosceles spider venom are the principal toxins responsible for the manifestation of dermonecrosis, intravascular hemolysis, and acute renal failure, which can result in death. These enzymes catalyze the hydrolysi ...

    Sphingomyelinases D (SMases D) from Loxosceles spider venom are the principal toxins responsible for the manifestation of dermonecrosis, intravascular hemolysis, and acute renal failure, which can result in death. These enzymes catalyze the hydrolysis of sphingomyelin, resulting in the formation of ceramide 1-phosphate and choline or the hydrolysis of lysophosphatidyl choline, generating the lipid mediator lysophosphatidic acid. This report represents the first crystal structure of a member of the sphingomyelinase D family from Loxosceles laeta (SMase I), which has been determined at 1.75-angstrom resolution using the "quick cryo-soaking" technique and phases obtained from a single iodine derivative and data collected from a conventional rotating anode x-ray source. SMase I folds as an (alpha/beta)8 barrel, the interfacial and catalytic sites encompass hydrophobic loops and a negatively charged surface. Substrate binding and/or the transition state are stabilized by a Mg2+ ion, which is coordinated by Glu32, Asp34, Asp91, and solvent molecules. In the proposed acid base catalytic mechanism, His12 and His47 play key roles and are supported by a network of hydrogen bonds between Asp34, Asp52, Trp230, Asp233, and Asn252.


    Related Citations: 
    • Crystallization and preliminary crystallographic analysis of SMase I, a sphingomyelinase from Loxosceles laeta spider venom.
      Zela, S.P.,Fernandes Pedrosa, M.F.,Murakami, M.T.,De Andrade, S.A.,Arni, R.K.,Tambourgi, D.V.
      (2004) Acta Crystallogr.,Sect.D 60: 1112


    Organizational Affiliation

    Department of Physics, Instituto de Biociências, Letras e Ciências Exatas/Universidade Estadual Paulista, São José do Rio Preto, SP 15054-000, Brazil.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Sphingomyelinase I
A, B, C, D
285Loxosceles laetaMutation(s): 0 
EC: 4.6.1.-
Find proteins for Q8I914 (Loxosceles laeta)
Go to UniProtKB:  Q8I914
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
EPE
Query on EPE

Download SDF File 
Download CCD File 
A, C, D
4-(2-HYDROXYETHYL)-1-PIPERAZINE ETHANESULFONIC ACID
HEPES
C8 H18 N2 O4 S
JKMHFZQWWAIEOD-UHFFFAOYSA-N
 Ligand Interaction
SO4
Query on SO4

Download SDF File 
Download CCD File 
A, B, C, D
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
MG
Query on MG

Download SDF File 
Download CCD File 
A, B, C, D
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.75 Å
  • R-Value Free: 0.225 
  • R-Value Work: 0.186 
  • Space Group: P 65
Unit Cell:
Length (Å)Angle (°)
a = 139.818α = 90.00
b = 139.818β = 90.00
c = 113.461γ = 120.00
Software Package:
Software NamePurpose
MAR345data collection
SHELXSphasing
REFMACrefinement
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2005-01-18
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2017-10-11
    Type: Refinement description