Literature summary for 2.3.1.57 extracted from

Montemayor, E.J.; Hoffman, D.W.
The crystal structure of spermidine/spermine N1-acetyltransferase in complex with spermine provides insights into substrate binding and catalysis (2008), Biochemistry, 47, 9145-9153.

Cloned(Commentary)

Cloned (Comment)	Organism
expression of His-tagged SSAt in Escherichia coli strain BL21(DE3)	Mus musculus

Crystallization (Commentary)

Crystallization (Comment)	Organism
SSAT in complex with coenzyme A, with and without bound spermine, hanging drop vapor diffusion method at 4°C, crystals of the binary complex between SSAT and CoA are obtained in 20% PEG 8000, 80 mM sodium acetate, 15% glycerol, 2 mM spermine, 1 mM CoA, and 85 mM sodium cacodylate, pH 6.0, 0.001 ml of the protein solution is mixed with 0.01 ml of precipitant solution containing 20% PEG 8000, 50 mM NaCl, 2 mM spermine, 1 mM coenzyme A, 15% glycerol, and 100 mM bicine buffer, pH 9.0. Crystals are obtained at pH 5.0-6.5 over a broad range of precipitant and salt concentrations. Introduction of spermine results in displacement of CoA from the enzyme active site. X-ray diffraction structure determination and analysis at 2.1-2.3 A resolution	Mus musculus

Crystallization (Comment)

Organism

SSAT in complex with coenzyme A, with and without bound spermine, hanging drop vapor diffusion method at 4°C, crystals of the binary complex between SSAT and CoA are obtained in 20% PEG 8000, 80 mM sodium acetate, 15% glycerol, 2 mM spermine, 1 mM CoA, and 85 mM sodium cacodylate, pH 6.0, 0.001 ml of the protein solution is mixed with 0.01 ml of precipitant solution containing 20% PEG 8000, 50 mM NaCl, 2 mM spermine, 1 mM coenzyme A, 15% glycerol, and 100 mM bicine buffer, pH 9.0. Crystals are obtained at pH 5.0-6.5 over a broad range of precipitant and salt concentrations. Introduction of spermine results in displacement of CoA from the enzyme active site. X-ray diffraction structure determination and analysis at 2.1-2.3 A resolution

Mus musculus

Protein Variants

Protein Variants	Comment	Organism
D93N	site-directed mutagenesis, the mutation affects both substrate binding and catalysis without changing the pH dependence of the enzyme	Mus musculus
E92Q	site-directed mutagenesis, the mutation has a detrimental effect on both substrate binding and catalysis and shifts the optimal pH for enzyme activity further into alkaline solution conditions	Mus musculus

Natural Substrates/ Products (Substrates)

Natural Substrates	Organism	Comment (Nat. Sub.)	Natural Products	Comment (Nat. Pro.)	Rev.
acetyl-CoA + 1,3-diaminopropane	Mus musculus	-	CoA + ?	-	?
acetyl-CoA + diethylenetriamine	Mus musculus	-	CoA + ?	-	?
acetyl-CoA + N1-acetylspermine	Mus musculus	-	CoA + N1,N12-diacetylspermine	-	?
acetyl-CoA + N1-methyl-1,3-diaminopropane	Mus musculus	-	CoA + ?	-	?
acetyl-CoA + spermidine	Mus musculus	-	CoA + N1-acetylspermidine	-	?
acetyl-CoA + spermine	Mus musculus	-	CoA + N1-acetylspermine	-	?
additional information	Mus musculus	SSAT catalyzes the transfer of acetyl groups from acetylcoenzyme A to spermidine and spermine, as part of a polyamine degradation pathway. No activity with putrescine, cadaverine, lysine, thialysine, amantadine, substrate specificity, overview	?	-	?

Organism

Organism	UniProt	Comment	Textmining
Mus musculus	P48026	-	-

Reaction

Reaction	Comment	Organism	Reaction ID
acetyl-CoA + an alkane-alpha,omega-diamine = CoA + an N-acetyldiamine	Glu92 functions as a catalytic base to drive an otherwise unfavorable deprotonation step at physiological pH. Spermine and the enzyme and form a proton wire between the side chain of Glu92 and the N1 amine of spermine, a single water molecule forms hydrogen bonds with the side chains of Glu92, Asp93, and the N4 amine of spermine, substrate binding structure, overview	Mus musculus	a

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.
acetyl-CoA + 1,3-diaminopropane	-	Mus musculus	CoA + ?	-	?
acetyl-CoA + diethylenetriamine	-	Mus musculus	CoA + ?	-	?
acetyl-CoA + N1-acetylspermine	-	Mus musculus	CoA + N1,N12-diacetylspermine	-	?
acetyl-CoA + N1-methyl-1,3-diaminopropane	-	Mus musculus	CoA + ?	-	?
acetyl-CoA + spermidine	-	Mus musculus	CoA + N1-acetylspermidine	-	?
acetyl-CoA + spermine	-	Mus musculus	CoA + N1-acetylspermine	-	?
acetyl-CoA + spermine	spermine and the enzyme and form a proton wire between the side chain of Glu92 and the N1 amine of spermine, a single water molecule forms hydrogen bonds with the side chains of Glu92, Asp93, and the N4 amine of spermine, substrate binding structure, overview	Mus musculus	CoA + N1-acetylspermine	-	?
additional information	SSAT catalyzes the transfer of acetyl groups from acetylcoenzyme A to spermidine and spermine, as part of a polyamine degradation pathway. No activity with putrescine, cadaverine, lysine, thialysine, amantadine, substrate specificity, overview	Mus musculus	?	-	?

Synonyms

Synonyms	Comment	Organism
More	SSAT belongs to the GCN5-related N-acetyltransferase, GNAT, superfamily of acetyltransferases	Mus musculus
spermidine/spermine N1-acetyltransferase	-	Mus musculus
SSAT	-	Mus musculus

Temperature Optimum [°C]

Temperature Optimum [°C]	Temperature Optimum Maximum [°C]	Comment	Organism
25	-	assay at	Mus musculus

pH Optimum

pH Optimum Minimum	pH Optimum Maximum	Comment	Organism
8.5	-	assay at	Mus musculus

Cofactor

Cofactor	Comment	Organism	Structure
acetyl-CoA	-	Mus musculus

General Information

General Information	Comment	Organism
metabolism	SSAT catalyzes the transfer of acetyl groups from acetylcoenzyme A to spermidine and spermine, as part of a polyamine degradation pathway	Mus musculus