1G20

MGATP-BOUND AND NUCLEOTIDE-FREE STRUCTURES OF A NITROGENASE PROTEIN COMPLEX BETWEEN LEU127DEL-FE PROTEIN AND THE MOFE PROTEIN


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.255 
  • R-Value Work: 0.218 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

MgATP-Bound and nucleotide-free structures of a nitrogenase protein complex between the Leu 127 Delta-Fe-protein and the MoFe-protein.

Chiu, H.Peters, J.W.Lanzilotta, W.N.Ryle, M.J.Seefeldt, L.C.Howard, J.B.Rees, D.C.

(2001) Biochemistry 40: 641-650

  • Primary Citation of Related Structures:  1G21

  • PubMed Abstract: 
  • A mutant form of the nitrogenase iron protein with a deletion of residue Leu 127, located in the switch II region of the nucleotide binding site, forms a tight, inactive complex with the nitrogenase molybdenum iron (MoFe) protein in the absence of nu ...

    A mutant form of the nitrogenase iron protein with a deletion of residue Leu 127, located in the switch II region of the nucleotide binding site, forms a tight, inactive complex with the nitrogenase molybdenum iron (MoFe) protein in the absence of nucleotide. The structure of this complex generated with proteins from Azotobacter vinelandii (designated the L127Delta-Av2-Av1 complex) has been crystallographically determined in the absence of nucleotide at 2.2 A resolution and with bound MgATP (introduced by soaking) at 3.0 A resolution. As observed in the structure of the complex between the wild-type A. vinelandii nitrogenase proteins stabilized with ADP.AlF(4-), the most significant conformational changes in the L127Delta complex occur in the Fe-protein component. While the interactions at the interface between the MoFe-protein and Fe-proteins are conserved in the two complexes, significant differences are evident at the subunit-subunit interface of the dimeric Fe-proteins, with the L127Delta-Av2 structure having a more open conformation than the wild-type Av2 in the complex stabilized by ADP.AlF(4-). Addition of MgATP to the L127Delta-Av2-Av1 complex results in a further increase in the separation between Fe-protein subunits so that the structure more closely resembles that of the wild-type, nucleotide-free, uncomplexed Fe-protein, rather than the Fe-protein conformation in the ADP.AlF(4-) complex. The L127Delta mutation precludes key interactions between the Fe-protein and nucleotide, especially, but not exclusively, in the region corresponding to the switch II region of G-proteins, where the deletion constrains Gly 128 and Asp 129 from forming hydrogen bonds to the gamma-phosphate and activating water for attack on this group, respectively. These alterations account for the inability of this mutant to support mechanistically productive ATP hydrolysis. The ability of the L127Delta-Av2-Av1 complex to bind MgATP demonstrates that dissociation of the nitrogenase complex is not required for nucleotide binding.


    Organizational Affiliation

    Division of Chemistry and Chemical Engineering, Mail Code 147-75CH, California Institute of Technology, Pasadena, California 91125, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
NITROGENASE MOLYBDENUM-IRON PROTEIN ALPHA CHAIN
A, C
492Azotobacter vinelandiiGene Names: nifD
EC: 1.18.6.1
Find proteins for P07328 (Azotobacter vinelandii)
Go to UniProtKB:  P07328
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
NITROGENASE MOLYBDENUM-IRON PROTEIN BETA CHAIN
B, D
523Azotobacter vinelandiiGene Names: nifK
EC: 1.18.6.1
Find proteins for P07329 (Azotobacter vinelandii)
Go to UniProtKB:  P07329
Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
NITROGENASE IRON PROTEIN
E, F, G, H
289Azotobacter vinelandiiGene Names: nifH1
EC: 1.18.6.1
Find proteins for P00459 (Azotobacter vinelandii)
Go to UniProtKB:  P00459
Small Molecules
Ligands 5 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SF4
Query on SF4

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Download CCD File 
E, G
IRON/SULFUR CLUSTER
Fe4 S4
LJBDFODJNLIPKO-VKOJMFJBAC
 Ligand Interaction
CFM
Query on CFM

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Download CCD File 
A, C
FE-MO-S CLUSTER
Fe7 Mo S9
UZRXIPMKRKMLQF-VGXFRCDIAP
 Ligand Interaction
CA
Query on CA

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Download CCD File 
B, D
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
CLF
Query on CLF

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Download CCD File 
B, D
FE(8)-S(7) CLUSTER
Fe8 S7
JKVMXLBGZBULKV-DHHOTQGYAO
 Ligand Interaction
HCA
Query on HCA

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Download CCD File 
A, C
3-HYDROXY-3-CARBOXY-ADIPIC ACID
C7 H10 O7
XKJVEVRQMLKSMO-SSDOTTSWSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.255 
  • R-Value Work: 0.218 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 264.240α = 90.00
b = 111.460β = 97.40
c = 121.590γ = 90.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
DENZOdata reduction
AMoREphasing
CNSrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2001-01-31
    Type: Initial release
  • Version 1.1: 2007-10-16
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Derived calculations, Version format compliance