2IZ6

Structure of the Chlamydomonas rheinhardtii Moco Carrier Protein


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.60 Å
  • R-Value Free: 0.231 
  • R-Value Work: 0.184 
  • R-Value Observed: 0.186 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Function and Structure of the Molybdenum Cofactor Carrier Protein from Chlamydomonas Reinhardtii.

Fischer, K.Llamas, A.Tejada-Jimenez, M.Schrader, N.Kuper, J.Ataya, F.S.Galvan, A.Mendel, R.R.Fernandez, E.Schwarz, G.

(2006) J Biol Chem 281: 30186

  • DOI: 10.1074/jbc.M603919200
  • Primary Citation of Related Structures:  
    2IZ5, 2IZ6, 2IZ7

  • PubMed Abstract: 
  • The molybdenum cofactor (Moco) forms the catalytic site in all eukaryotic molybdenum enzymes and is synthesized by a multistep biosynthetic pathway. The mechanism of transfer, storage, and insertion of Moco into the appropriate apo-enzyme is poorly understood ...

    The molybdenum cofactor (Moco) forms the catalytic site in all eukaryotic molybdenum enzymes and is synthesized by a multistep biosynthetic pathway. The mechanism of transfer, storage, and insertion of Moco into the appropriate apo-enzyme is poorly understood. In Chlamydomonas reinhardtii, a Moco carrier protein (MCP) has been identified and characterized recently. Here we show biochemical evidence that MCP binds Moco as well as the tungstate-substituted form of the cofactor (Wco) with high affinity, whereas molybdopterin, the ultimate cofactor precursor, is not bound. This binding selectivity points to a specific metal-mediated interaction with MCP, which protects Moco and Wco from oxidation with t((1/2)) of 24 and 96 h, respectively. UV-visible spectroscopy showed defined absorption bands at 393, 470, and 570 nm pointing to ene-diothiolate and protein side-chain charge transfer bonds with molybdenum. We have determined the crystal structure of MCP at 1.6 Angstrom resolution using seleno-methionated and native protein. The monomer constitutes a Rossmann fold with two homodimers forming a symmetrical tetramer in solution. Based on conserved surface residues, charge distribution, shape, in silico docking studies, structural comparisons, and identification of an anionbinding site, a prominent surface depression was proposed as a Moco-binding site, which was confirmed by structure-guided mutagenesis coupled to substrate binding studies.


    Organizational Affiliation

    Institute of Plant Biology, Technical University Braunschweig, 38106 Braunschweig, Germany.



Macromolecules
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Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
MOLYBDENUM COFACTOR CARRIER PROTEINA, B176Chlamydomonas reinhardtiiMutation(s): 0 
Gene Names: MCPMCP1CHLRE_09g390050v5CHLREDRAFT_190981
UniProt
Find proteins for Q8RV61 (Chlamydomonas reinhardtii)
Explore Q8RV61 
Go to UniProtKB:  Q8RV61
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ8RV61
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.60 Å
  • R-Value Free: 0.231 
  • R-Value Work: 0.184 
  • R-Value Observed: 0.186 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 68.079α = 90
b = 126.009β = 90
c = 75.68γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
DENZOdata reduction
SCALEPACKdata scaling
AMoREphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2006-07-26
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Advisory, Refinement description, Version format compliance