Crystallization (Comment) | Organism |
---|---|
enzyme in ligand-free form or complxed with spermine or spermidine, and/or acetyl-CoA, X-ray diffraction structure determination and analysis at 1.85-2.83 A resolution, the enzyme occurs in open and closed conformations | Vibrio cholerae |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
additional information | - |
additional information | allosteric substrate binding, polyamine allosteric site structure, complex enzyme behavior, it exhibits sigmoidal curves and substrate inhibition, bireactant random steady-state kinetic mechanism, detailed non-linear regression kinetic analysis, overview | Vibrio cholerae |
Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
---|---|---|---|
270000 | - |
polyamine-bound enzyme, gel filtration and small-angle X-ray scattering analysis | Vibrio cholerae |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
3 acetyl-CoA + 2 spermine | Vibrio cholerae | - |
3 CoA + N1-acetylspermine + N1,N12-diacetylspermine | - |
? | |
3 acetyl-CoA + 2 spermine | Vibrio cholerae N16961 | - |
3 CoA + N1-acetylspermine + N1,N12-diacetylspermine | - |
? | |
3 acetyl-CoA + spermidine | Vibrio cholerae | - |
3 CoA + N1,N4,N8-triacetylspermidine | - |
? | |
3 acetyl-CoA + spermidine | Vibrio cholerae N16961 | - |
3 CoA + N1,N4,N8-triacetylspermidine | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Vibrio cholerae | Q9KL03 | serotype O1, gene speG or VCA0947 | - |
Vibrio cholerae N16961 | Q9KL03 | serotype O1, gene speG or VCA0947 | - |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
3 acetyl-CoA + 2 spermine | - |
Vibrio cholerae | 3 CoA + N1-acetylspermine + N1,N12-diacetylspermine | - |
? | |
3 acetyl-CoA + 2 spermine | - |
Vibrio cholerae N16961 | 3 CoA + N1-acetylspermine + N1,N12-diacetylspermine | - |
? | |
3 acetyl-CoA + spermidine | - |
Vibrio cholerae | 3 CoA + N1,N4,N8-triacetylspermidine | - |
? | |
3 acetyl-CoA + spermidine | - |
Vibrio cholerae N16961 | 3 CoA + N1,N4,N8-triacetylspermidine | - |
? | |
additional information | spermine and spermidine are the preferential substrates, no activity with cadaverine. Conformational differences between enzyme SpeG ligand-free and liganded structures, allosteric substrate binding site structure, overview | Vibrio cholerae | ? | - |
? | |
additional information | spermine and spermidine are the preferential substrates, no activity with cadaverine. Conformational differences between enzyme SpeG ligand-free and liganded structures, allosteric substrate binding site structure, overview | Vibrio cholerae N16961 | ? | - |
? |
Subunits | Comment | Organism |
---|---|---|
dodecamer | three-dimensional structure in several ligand-free and ligand-bound structures, overview. The enzyme monomer has a mixed alpha/beta architecture | Vibrio cholerae |
More | the enzyme occurs in open and closed conformations | Vibrio cholerae |
Synonyms | Comment | Organism |
---|---|---|
SpeG | - |
Vibrio cholerae |
spermidine N-acetyltransferase | - |
Vibrio cholerae |
VCA0947 | - |
Vibrio cholerae |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
acetyl-CoA | cofactor-binding site structure, overview. The beta-bulge formed by the beta4 and beta5 parallel strands is where the pantotheine moiety of AcCoA is located in the active site, characteristic for members of the GNAT superfamily. The pantothenate moiety forms hydrogen bonds with two conserved residues Ile87 and Ile89 | Vibrio cholerae |
General Information | Comment | Organism |
---|---|---|
evolution | the enzyme is a member of the Gcn5-related N-acetyltransferase superfamily | Vibrio cholerae |
metabolism | the enzyme is involved in regulation of polyamine levels in bacteria during pathogenesis | Vibrio cholerae |
additional information | enzyme SpeG forms dodecamers in solution and in crystals, three-dimensional structure in several ligand-free and liganded structures, the enzyme occurs in open and closed conformations, overview. Conserved residue Tyr134 is proposed to function as the general acid to protonate the thiolate anion of CoA after transfer of the acetyl group to the substrate | Vibrio cholerae |
physiological function | the enzyme catalyzes the initial step in the degradation of polyamines and is a critical enzyme for determining the polyamine concentrations in bacteria | Vibrio cholerae |