1GKA

The molecular basis of the coloration mechanism in lobster shell. beta-crustacyanin at 3.2 A resolution


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.23 Å
  • R-Value Free: 0.252 
  • R-Value Work: 0.213 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

The Molecular Basis of the Coloration Mechanism in Lobster Shell: Beta -Crustacyanin at 3.2-A Resolution

Cianci, M.Rizkallah, P.Olczak, A.Raftery, J.Chayen, N.Zagalsky, P.Helliwell, J.

(2002) Proc.Natl.Acad.Sci.USA 99: 9795

  • DOI: 10.1073/pnas.152088999

  • PubMed Abstract: 
  • The binding of the carotenoid astaxanthin (AXT) in the protein multimacromolecular complex crustacyanin (CR) is responsible for the blue coloration of lobster shell. The structural basis of the bathochromic shift mechanism has long been elusive. A ch ...

    The binding of the carotenoid astaxanthin (AXT) in the protein multimacromolecular complex crustacyanin (CR) is responsible for the blue coloration of lobster shell. The structural basis of the bathochromic shift mechanism has long been elusive. A change in color occurs from the orange red of the unbound dilute AXT (lambda(max) 472 nm in hexane), the well-known color of cooked lobster, to slate blue in the protein-bound live lobster state (lambda(max) 632 nm in CR). Intriguingly, extracted CR becomes red on dehydration and on rehydration goes back to blue. Recently, the innovative use of softer x-rays and xenon derivatization yielded the three-dimensional structure of the A(1) apoprotein subunit of CR, confirming it as a member of the lipocalin superfamily. That work provided the molecular replacement search model for a crystal form of the beta-CR holo complex, that is an A(1) with A(3) subunit assembly including two bound AXT molecules. We have thereby determined the structure of the A(3) molecule de novo. Lobster has clearly evolved an intricate structural mechanism for the coloration of its shell using AXT and a bathochromic shift. Blue/purple AXT proteins are ubiquitous among invertebrate marine animals, particularly the Crustacea. The three-dimensional structure of beta-CR has identified the protein contacts and structural alterations needed for the AXT color regulation mechanism.


    Organizational Affiliation

    Department of Chemistry, University of Manchester, Manchester M13 9PL, United Kingdom.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
CRUSTACYANIN A1 SUBUNIT
A
180Homarus gammarusN/A
Find proteins for P58989 (Homarus gammarus)
Go to UniProtKB:  P58989
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
CRUSTACYANIN A2 SUBUNIT
B
174Homarus gammarusN/A
Find proteins for P80007 (Homarus gammarus)
Go to UniProtKB:  P80007
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
EPE
Query on EPE

Download SDF File 
Download CCD File 
B
4-(2-HYDROXYETHYL)-1-PIPERAZINE ETHANESULFONIC ACID
HEPES
C8 H18 N2 O4 S
JKMHFZQWWAIEOD-UHFFFAOYSA-N
 Ligand Interaction
AXT
Query on AXT

Download SDF File 
Download CCD File 
A, B
ASTAXANTHIN
3,3'-DIHYDROXY-BETA,BETA-CAROTENE-4,4'-DIONE
C40 H52 O4
MQZIGYBFDRPAKN-UWFIBFSHSA-N
 Ligand Interaction
D12
Query on D12

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Download CCD File 
A
DODECANE
C12 H26
SNRUBQQJIBEYMU-UHFFFAOYSA-N
 Ligand Interaction
TRS
Query on TRS

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Download CCD File 
B
2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL
TRIS BUFFER
C4 H12 N O3
LENZDBCJOHFCAS-UHFFFAOYSA-O
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.23 Å
  • R-Value Free: 0.252 
  • R-Value Work: 0.213 
  • Space Group: P 63 2 2
Unit Cell:
Length (Å)Angle (°)
a = 155.466α = 90.00
b = 155.466β = 90.00
c = 168.504γ = 120.00
Software Package:
Software NamePurpose
AMoREphasing
DENZOdata reduction
CNSrefinement
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2002-08-08
    Type: Initial release
  • Version 1.1: 2011-05-08
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance