2B3V

Spermine spermidine acetyltransferase in complex with acetylcoa, K26R mutant


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.257 
  • R-Value Work: 0.222 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Structures of wild-type and mutant human spermidine/spermine N1-acetyltransferase, a potential therapeutic drug target.

Bewley, M.C.Graziano, V.Jiang, J.Matz, E.Studier, F.W.Pegg, A.E.Coleman, C.S.Flanagan, J.M.

(2006) Proc.Natl.Acad.Sci.USA 103: 2063-2068

  • DOI: 10.1073/pnas.0511008103
  • Primary Citation of Related Structures:  2B3U, 2B4B, 2B4D, 2B58, 2B5G

  • PubMed Abstract: 
  • Spermidine/spermine N1-acetyltransferase (SSAT) is a key enzyme in the control of polyamine levels in human cells, as acetylation of spermidine and spermine triggers export or degradation. Increased intracellular polyamine levels accompany several ty ...

    Spermidine/spermine N1-acetyltransferase (SSAT) is a key enzyme in the control of polyamine levels in human cells, as acetylation of spermidine and spermine triggers export or degradation. Increased intracellular polyamine levels accompany several types of cancers as well as other human diseases, and compounds that affect the expression, activity, or stability of SSAT are being explored as potential therapeutic drugs. We have expressed human SSAT from the cloned cDNA in Escherichia coli and have determined high-resolution structures of wild-type and mutant SSAT, as the free dimer and in binary and ternary complexes with CoA, acetyl-CoA (AcCoA), spermine, and the inhibitor N1,N11bis-(ethyl)-norspermine (BE-3-3-3). These structures show details of binding sites for cofactor, substrates, and inhibitor and provide a framework to understand enzymatic activity, mutations, and the action of potential drugs. Two dimer conformations were observed: a symmetric form with two open surface channels capable of binding substrate or cofactor, and an asymmetric form in which only one of the surface channels appears capable of binding and acetylating polyamines. SSAT was found to self-acetylate lysine-26 in the presence of AcCoA and absence of substrate, a reaction apparently catalzyed by AcCoA bound in the second channel of the asymmetric dimer. These unexpected and intriguing complexities seem likely to have some as yet undefined role in regulating SSAT activity or stability as a part of polyamine homeostasis. Sequence signatures group SSAT with proteins that appear to have thialysine Nepsilon-acetyltransferase activity.


    Organizational Affiliation

    Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Diamine acetyltransferase 1
A
171Homo sapiensGene Names: SAT1 (SAT)
EC: 2.3.1.57
Find proteins for P21673 (Homo sapiens)
Go to Gene View: SAT1
Go to UniProtKB:  P21673
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ACO
Query on ACO

Download SDF File 
Download CCD File 
A
ACETYL COENZYME *A
C23 H38 N7 O17 P3 S
ZSLZBFCDCINBPY-ZSJPKINUSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
MSE
Query on MSE
A
L-PEPTIDE LINKINGC5 H11 N O2 SeMET
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.257 
  • R-Value Work: 0.222 
  • Space Group: P 62
Unit Cell:
Length (Å)Angle (°)
a = 62.994α = 90.00
b = 62.994β = 90.00
c = 80.909γ = 120.00
Software Package:
Software NamePurpose
HKL-2000data collection
SOLVEphasing
SCALEPACKdata scaling
HKL-2000data reduction
CNSrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2006-01-17
    Type: Initial release
  • Version 1.1: 2008-05-01
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Derived calculations, Version format compliance
  • Version 1.3: 2015-06-24
    Type: Data collection, Database references