1BQD

ASPARTATE AMINOTRANSFERASE P138A/P195A DOUBLE MUTANT


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.204 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Functional and structural analysis of cis-proline mutants of Escherichia coli aspartate aminotransferase.

Birolo, L.Malashkevich, V.N.Capitani, G.De Luca, F.Moretta, A.Jansonius, J.N.Marino, G.

(1999) Biochemistry 38: 905-913

  • DOI: 10.1021/bi981467d
  • Primary Citation of Related Structures:  1BQA

  • PubMed Abstract: 
  • To elucidate the role of the two conserved cis-proline residues of aspartate aminotransferase (AspAT), one double and two single mutants of the enzyme from Escherichia coli (EcAspAT) were prepared: P138A, P195A and P138A/P195A in which the two prolin ...

    To elucidate the role of the two conserved cis-proline residues of aspartate aminotransferase (AspAT), one double and two single mutants of the enzyme from Escherichia coli (EcAspAT) were prepared: P138A, P195A and P138A/P195A in which the two prolines were replaced by alanine. The crystal structures of P195A and P138A/P195A have been determined at 2.3-2.1 A resolution. The wild-type geometry, including the cis conformation of the 194-195 peptide bond is retained upon substitution of proline 195 by alanine, whereas the trans conformation is adopted at the 137-138 peptide bond. Quite surprisingly, the replacement of each of the two prolines by alanine does not significantly affect either the activity or the stability of the protein. All the three mutants follow the same pathway as the wild type for unfolding equilibrium induced by guanidine hydrochloride [Herold, M., and Kirschner, K. (1990) Biochemistry 29, 1907-1913]. The kinetics of renaturation of P195A, where the alanine retains the wild-type cis conformation, is faster than wild type, whereas renaturation of P138A, which adopts the trans conformation, is slower. We conclude that cis-prolines seem to have been retained throughout the evolution of aspartate aminotransferase to possibly play a subtle role in directing the traffic of intermediates toward the unique structure of the native state, rather than to respond to the needs for a specific catalytic or functional role.


    Organizational Affiliation

    Dipartimento di Chimica Organica e Biologica, Università "Federico II", Napoli, Italy.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
ASPARTATE AMINOTRANSFERASE
A, B
396Escherichia coli (strain K12)Gene Names: aspC
EC: 2.6.1.1
Find proteins for P00509 (Escherichia coli (strain K12))
Go to UniProtKB:  P00509
Small Molecules
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
LLP
Query on LLP
A, B
L-PEPTIDE LINKINGC14 H22 N3 O7 PLYS
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.204 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 88.490α = 90.00
b = 79.880β = 119.58
c = 89.680γ = 90.00
Software Package:
Software NamePurpose
XDSdata reduction
TNTrefinement
AGROVATAdata scaling
AMoREphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1999-05-11
    Type: Initial release
  • Version 1.1: 2008-03-03
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance