2BUF

Arginine Feed-Back Inhibitable Acetylglutamate Kinase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.95 Å
  • R-Value Free: 0.267 
  • R-Value Work: 0.249 

wwPDB Validation 3D Report Full Report


This is version 1.4 of the entry. See complete history

Literature

Structural Bases of Feed-Back Control of Arginine Biosynthesis, Revealed by the Structure of Two Hexameric N-Acetylglutamate Kinases, from Thermotoga Maritima and Pseudomonas Aeruginosa

Ramon-Maiques, S.Fernandez-Murga, M.L.Gil-Ortiz, F.Vagin, A.Fita, I.Rubio, V.

(2006) J.Mol.Biol. 356: 695

  • DOI: 10.1016/j.jmb.2005.11.079
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • N-Acetylglutamate kinase (NAGK) catalyses the second step in the route of arginine biosynthesis. In many organisms this enzyme is inhibited by the final product of the route, arginine, and thus plays a central regulatory role. In addition, in photosy ...

    N-Acetylglutamate kinase (NAGK) catalyses the second step in the route of arginine biosynthesis. In many organisms this enzyme is inhibited by the final product of the route, arginine, and thus plays a central regulatory role. In addition, in photosynthetic organisms NAGK is the target of the nitrogen-signalling protein PII. The 3-D structure of homodimeric, arginine-insensitive, Escherichia coli NAGK, clarified substrate binding and catalysis but shed no light on arginine inhibition of NAGK. We now shed light on arginine inhibition by determining the crystal structures, at 2.75 A and 2.95 A resolution, of arginine-complexed Thermotoga maritima and arginine-free Pseudomonas aeruginosa NAGKs, respectively. Both enzymes are highly similar ring-like hexamers having a central orifice of approximately 30 A diameter. They are formed by linking three E.coli NAGK-like homodimers through the interlacing of an N-terminal mobile kinked alpha-helix, which is absent from E.coli NAGK. Arginine is bound in each subunit of T.maritima NAGK, flanking the interdimeric junction, in a site formed between the N helix and the C lobe of the subunit. This site is also present, in variable conformations, in P.aeruginosa NAGK, but is missing from E.coli NAGK. Arginine, by gluing the C lobe of each subunit to the inter-dimeric junction, may stabilize an enlarged active centre conformation, hampering catalysis. Acetylglutamate counters arginine inhibition by promoting active centre closure. The hexameric architecture justifies the observed sigmoidal arginine inhibition kinetics with a high Hill coefficient (N approximately 4), and appears essential for arginine inhibition and for NAGK-PII complex formation, since this complex may involve binding of NAGK and PII with their 3-fold axes aligned. The NAGK structures allow identification of diagnostic sequence signatures for arginine inhibition. These signatures are found also in the homologous arginine-inhibited enzyme NAG synthase. The findings on NAGK shed light on the structure, function and arginine inhibition of this synthase, for which a hexameric model is constructed.


    Related Citations: 
    • Towards Structural Understanding of Feedback Control of Arginine Biosynthesis: Cloning and Expression of the Gene for the Arginine-Inhibited N-Acetyl-L-Glutamate Kinase from Pseudomonas Aeruginosa, Purification and Crystallization of the Recombinant Enzyme and Preliminary X-Ray Studies
      Fernandez-Murga, M.L.,Ramon-Maiques, S.,Gil-Ortiz, F.,Fita, I.,Rubio, V.
      (2002) Acta Crystallogr.,Sect.D 58: 1045


    Organizational Affiliation

    Instituto de Biomedicina de Valencia (CSIC), Jaume Roig 11, Valencia 46010, Spain.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
ACETYLGLUTAMATE KINASE
A, B, C, D, E, F, G, H, I, J, K, L
300Pseudomonas aeruginosa (strain ATCC 15692 / DSM 22644 / CIP 104116 / JCM 14847 / LMG 12228 / 1C / PRS 101 / PAO1)Mutation(s): 0 
Gene Names: argB
EC: 2.7.2.8
Find proteins for Q9HTN2 (Pseudomonas aeruginosa (strain ATCC 15692 / DSM 22644 / CIP 104116 / JCM 14847 / LMG 12228 / 1C / PRS 101 / PAO1))
Go to UniProtKB:  Q9HTN2
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ADP
Query on ADP

Download SDF File 
Download CCD File 
B, C, D, E, F, G, H, I, J, L
ADENOSINE-5'-DIPHOSPHATE
C10 H15 N5 O10 P2
XTWYTFMLZFPYCI-KQYNXXCUSA-N
 Ligand Interaction
CL
Query on CL

Download SDF File 
Download CCD File 
B, C, D, G, H, L
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
MG
Query on MG

Download SDF File 
Download CCD File 
B, C, D, E, G, H, I, L
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
NLG
Query on NLG

Download SDF File 
Download CCD File 
A, B, D, E, F, G, H, I, K, L
N-ACETYL-L-GLUTAMATE
C7 H11 N O5
RFMMMVDNIPUKGG-YFKPBYRVSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.95 Å
  • R-Value Free: 0.267 
  • R-Value Work: 0.249 
  • Space Group: P 1
Unit Cell:
Length (Å)Angle (°)
a = 71.860α = 91.49
b = 98.780β = 92.03
c = 162.900γ = 107.56
Software Package:
Software NamePurpose
SCALAdata scaling
MOLREPphasing
CNSrefinement
MOSFLMdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2005-12-13
    Type: Initial release
  • Version 1.1: 2011-05-08
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2019-03-06
    Type: Data collection, Experimental preparation, Other
  • Version 1.4: 2019-05-08
    Type: Data collection, Experimental preparation