1SQC

SQUALENE-HOPENE-CYCLASE FROM ALICYCLOBACILLUS ACIDOCALDARIUS


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.85 Å
  • R-Value Free: 0.243 
  • R-Value Work: 0.167 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structure and function of a squalene cyclase.

Wendt, K.U.Poralla, K.Schulz, G.E.

(1997) Science 277: 1811-1815

  • Also Cited By: 1UMP, 1GSZ, 1O79, 1O6R, 1O6Q, 1O6H, 1H3C, 1H3B, 1H3A, 1H39, 1H37, 1H36, 1H35

  • PubMed Abstract: 
  • The crystal structure of squalene-hopene cyclase from Alicyclobacillus acidocaldarius was determined at 2.9 angstrom resolution. The mechanism and sequence of this cyclase are closely related to those of 2,3-oxidosqualene cyclases that catalyze the c ...

    The crystal structure of squalene-hopene cyclase from Alicyclobacillus acidocaldarius was determined at 2.9 angstrom resolution. The mechanism and sequence of this cyclase are closely related to those of 2,3-oxidosqualene cyclases that catalyze the cyclization step in cholesterol biosynthesis. The structure reveals a membrane protein with membrane-binding characteristics similar to those of prostaglandin-H2 synthase, the only other reported protein of this type. The active site of the enzyme is located in a large central cavity that is of suitable size to bind squalene in its required conformation and that is lined by aromatic residues. The structure supports a mechanism in which the acid starting the reaction by protonating a carbon-carbon double bond is an aspartate that is coupled to a histidine. Numerous surface alpha helices are connected by characteristic QW-motifs (Q is glutamine and W is tryptophan) that tighten the protein structure, possibly for absorbing the reaction energy without structural damage.


    Related Citations: 
    • Crystallization and Preliminary X-Ray Crystallographic Analysis of Squalene-Hopene Cyclase from Alicyclobacillus Acidocaldarius
      Wendt, K.U.,Feil, C.,Lenhart, A.,Poralla, K.,Schulz, G.E.
      (1997) Protein Sci. 6: 722


    Organizational Affiliation

    Institut für Organische Chemie und Biochemie, Albertstrasse 21, D-79104 Freiburg im Breisgau, Germany.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
SQUALENE-HOPENE CYCLASE
A
631Alicyclobacillus acidocaldarius subsp. acidocaldarius (strain ATCC 27009 / DSM 446 / JCM 5260 / NBRC 15652 / NCIMB 11725 / NRRL B-14509 / 104-1A)Mutation(s): 0 
Gene Names: shc
EC: 4.2.1.129, 5.4.99.17
Find proteins for P33247 (Alicyclobacillus acidocaldarius subsp. acidocaldarius (strain ATCC 27009 / DSM 446 / JCM 5260 / NBRC 15652 / NCIMB 11725 / NRRL B-14509 / 104-1A))
Go to UniProtKB:  P33247
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
LDA
Query on LDA

Download SDF File 
Download CCD File 
A
LAURYL DIMETHYLAMINE-N-OXIDE
C14 H31 N O
SYELZBGXAIXKHU-UHFFFAOYSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
LDAKi: 140 nM PDBBIND
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.85 Å
  • R-Value Free: 0.243 
  • R-Value Work: 0.167 
  • Space Group: P 3 2 1
Unit Cell:
Length (Å)Angle (°)
a = 140.700α = 90.00
b = 140.700β = 90.00
c = 81.900γ = 120.00
Software Package:
Software NamePurpose
X-PLORmodel building
XSCALEdata scaling
X-PLORrefinement
X-PLORphasing
XDSdata reduction
CCP4data scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1997-12-17
    Type: Initial release
  • Version 1.1: 2008-03-24
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance