2LVW

Solution NMR studies of the dimeric regulatory subunit IlvN of the E.coli Acetohydroxyacid synthase I (AHAS I)


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with the lowest energy 

wwPDB Validation 3D Report Full Report


This is version 1.0 of the entry. See complete history

Literature

The coil-to-helix transition in IlvN regulates the allosteric control of Escherichia coli acetohydroxyacid synthase I

Karanth, N.M.Sarma, S.P.

(2013) Biochemistry 52: 70-83

  • DOI: 10.1021/bi301415m
  • Also Cited By: 5YUM, 5YPY, 5YPW, 5YPP

  • PubMed Abstract: 
  • The solution structure of IlvN, the regulatory subunit of Escherichia coli acetohydroxyacid synthase I, in the valine-bound form has been determined using high-resolution multidimensional, multinuclear nuclear magnetic resonance (NMR) methods. IlvN i ...

    The solution structure of IlvN, the regulatory subunit of Escherichia coli acetohydroxyacid synthase I, in the valine-bound form has been determined using high-resolution multidimensional, multinuclear nuclear magnetic resonance (NMR) methods. IlvN in the presence or absence of the effector molecule is present as a 22.5 kDa dimeric molecule. The ensemble of 20 low-energy structures shows a backbone root-mean-square deviation of 0.73 ± 0.13 Å and a root-mean-square deviation of 1.16 ± 0.13 Å for all heavy atoms. Furthermore, more than 98% of the backbone φ and ψ dihedral angles occupy the allowed and additionally allowed regions of the Ramachandran map, which is indicative of the fact that the structures are of high stereochemical quality. Each protomer exhibits a βαββαβα topology that is a characteristic feature of the ACT domain seen in metabolic enzymes. In the valine-bound form, IlvN exists apparently as a single conformer. In the free form, IlvN exists as a mixture of conformational states that are in intermediate exchange on the NMR time scale. Thus, a large shift in the conformational equilibrium is observed upon going from the free form to the bound form. The structure of the valine-bound form of IlvN was found to be similar to that of the ACT domain of the unliganded form of IlvH. Comparisons of the structures of the unliganded forms of these proteins suggest significant differences. The structural and conformational properties of IlvN determined here have allowed a better understanding of the mechanism of regulation of branched chain amino acid biosynthesis.


    Organizational Affiliation

    Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, Karnataka, India.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Acetolactate synthase isozyme 1 small subunit
A, B
98Escherichia coli (strain K12)Mutation(s): 0 
Gene Names: ilvN
EC: 2.2.1.6
Find proteins for P0ADF8 (Escherichia coli (strain K12))
Go to UniProtKB:  P0ADF8
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with the lowest energy 
  • Olderado: 2LVW Olderado

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2013-05-29
    Type: Initial release