2NU8

C123aT Mutant of E. coli Succinyl-CoA Synthetase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.15 Å
  • R-Value Free: 0.255 
  • R-Value Work: 0.210 
  • R-Value Observed: 0.215 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Participation of Cys 123alpha of Escherichia coli Succinyl-CoA Synthetase in Catalysis

Hidber, E.Brownie, E.R.Hayakawa, K.Fraser, M.E.

(2007) Acta Crystallogr D Biol Crystallogr 63: 876-884

  • DOI: 10.1107/S0907444907029319
  • Primary Citation of Related Structures:  
    2NU8, 2NU7, 2NU6, 2NU9, 2NUA

  • PubMed Abstract: 
  • Succinyl-CoA synthetase has a highly conserved cysteine residue, Cys123alpha in the Escherichia coli enzyme, that is located near the CoA-binding site and the active-site histidine residue. To test whether the succinyl moiety of succinyl-CoA is transferred to the thiol of Cys123alpha as part of the catalytic mechanism, this residue was mutated to alanine, serine, threonine and valine ...

    Succinyl-CoA synthetase has a highly conserved cysteine residue, Cys123alpha in the Escherichia coli enzyme, that is located near the CoA-binding site and the active-site histidine residue. To test whether the succinyl moiety of succinyl-CoA is transferred to the thiol of Cys123alpha as part of the catalytic mechanism, this residue was mutated to alanine, serine, threonine and valine. Each mutant protein was catalytically active, although less active than the wild type. This proved that the specific formation of a thioester bond with Cys123alpha is not part of the catalytic mechanism. To understand why the mutations affected catalysis, the crystal structures of the four mutant proteins were determined. The alanine mutant showed no structural changes yet had reduced activity, suggesting that the size of the cysteine is important for optimal activity. These results explain why this cysteine residue is conserved in the sequences of succinyl-CoA synthetases from different sources.


    Organizational Affiliation

    Department of Biochemistry, University of Western Ontario, London, Ontario, Canada.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Succinyl-CoA ligase [ADP-forming] subunit alphaA, C [auth D]288Escherichia coliMutation(s): 1 
Gene Names: sucD
EC: 6.2.1.5
Find proteins for P0AGE9 (Escherichia coli (strain K12))
Explore P0AGE9 
Go to UniProtKB:  P0AGE9
Protein Feature View
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Succinyl-CoA synthetase beta chainB, D [auth E]388Escherichia coliMutation(s): 0 
Gene Names: sucC
EC: 6.2.1.5
Find proteins for P0A836 (Escherichia coli (strain K12))
Explore P0A836 
Go to UniProtKB:  P0A836
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.15 Å
  • R-Value Free: 0.255 
  • R-Value Work: 0.210 
  • R-Value Observed: 0.215 
  • Space Group: P 43 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 96.69α = 90
b = 96.69β = 90
c = 385.94γ = 90
Software Package:
Software NamePurpose
ADSCdata collection
CNSrefinement
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

  • Deposited Date: 2006-11-08 
  • Released Date: 2007-07-24 
  • Deposition Author(s): Fraser, M.E.

Revision History  (Full details and data files)

  • Version 1.0: 2007-07-24
    Type: Initial release
  • Version 1.1: 2008-05-01
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Non-polymer description, Version format compliance