1PO9

Crytsal structure of isoaspartyl dipeptidase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.229 
  • R-Value Work: 0.198 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

X-ray structure of isoaspartyl dipeptidase from E.coli: a dinuclear zinc peptidase evolved from amidohydrolases.

Jozic, D.Kaiser, J.T.Huber, R.Bode, W.Maskos, K.

(2003) J Mol Biol 332: 243-256

  • DOI: 10.1016/s0022-2836(03)00845-3
  • Primary Citation of Related Structures:  
    1POK, 1POJ, 1PO9

  • PubMed Abstract: 
  • L-aspartyl and L-asparaginyl residues in proteins spontaneously undergo intra-residue rearrangements forming isoaspartyl/beta-aspartyl residues linked through their side-chain beta-carboxyl group with the following amino acid. In order to avoid accumulation of isoaspartyl dipeptides left over from protein degradation, some bacteria have developed specialized isoaspartyl/beta-aspartyl zinc dipeptidases sequentially unrelated to other peptidases, which also poorly degrade alpha-aspartyl dipeptides ...

    L-aspartyl and L-asparaginyl residues in proteins spontaneously undergo intra-residue rearrangements forming isoaspartyl/beta-aspartyl residues linked through their side-chain beta-carboxyl group with the following amino acid. In order to avoid accumulation of isoaspartyl dipeptides left over from protein degradation, some bacteria have developed specialized isoaspartyl/beta-aspartyl zinc dipeptidases sequentially unrelated to other peptidases, which also poorly degrade alpha-aspartyl dipeptides. We have expressed and crystallized the 390 amino acid residue isoaspartyl dipeptidase (IadA) from E.coli, and have determined its crystal structure in the absence and presence of the phosphinic inhibitor Asp-Psi[PO(2)CH(2)]-LeuOH. This structure reveals an octameric particle of 422 symmetry, with each polypeptide chain organized in a (alphabeta)(8) TIM-like barrel catalytic domain attached to a U-shaped beta-sandwich domain. At the C termini of the beta-strands of the beta-barrel, the two catalytic zinc ions are surrounded by four His, a bridging carbamylated Lys and an Asp residue, which seems to act as a proton shuttle. A large beta-hairpin loop protruding from the (alphabeta)(8) barrel is disordered in the free peptidase, but forms a flap that stoppers the barrel entrance to the active center upon binding of the dipeptide mimic. This isoaspartyl dipeptidase shows strong topological homology with the alpha-subunit of the binickel-containing ureases, the dinuclear zinc dihydroorotases, hydantoinases and phosphotriesterases, and the mononuclear adenosine and cytosine deaminases, which all are catalyzing hydrolytic reactions at carbon or phosphorous centers. Thus, nature has adapted an existing fold with catalytic tools suitable for hydrolysis of amide bonds to the binding requirements of a peptidase.


    Organizational Affiliation

    Max-Planck-Institut für Biochemie, Abteilung Strukturforschung, Am Klopferspitz 18a, D-82152 Martinsried, Germany.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Isoaspartyl dipeptidase AB390Escherichia coliMutation(s): 1 
EC: 3.4.19
Find proteins for P39377 (Escherichia coli (strain K12))
Explore P39377 
Go to UniProtKB:  P39377
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
KCX
Query on KCX
A,BL-PEPTIDE LINKINGC7 H14 N2 O4LYS
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.229 
  • R-Value Work: 0.198 
  • Space Group: P 4 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 116.644α = 90
b = 116.644β = 90
c = 137.12γ = 90

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2004-06-22
    Type: Initial release
  • Version 1.1: 2008-04-29
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Version format compliance