2.5.1.22	D201A	40000fold decrease in ratio kcat/Km value	687717	
2.5.1.22	D201A	mutation of Asp201 to Ala decreases the kcat/Km for decarboxylated S-adenosylmethionine by more than 100000fold	692270	
2.5.1.22	D201N	40000fold decrease in ratio kcat/Km value	687717	
2.5.1.22	D201N	mutation of Asp201 to Asn decreases the kcat/Km for decarboxylated S-adenosylmethionine by more than 100000fold	692270	
2.5.1.22	D276N	250000fold decrease in ratio kcat/Km value	687717	
2.5.1.22	D276N	alteration of this residue reduces the kcat/Km for spermidine by more than 200000fold	692270	
2.5.1.22	DELTA1-129	0.02% activity compared to the wild-type enzyme	692270	
2.5.1.22	DELTA1-145	no activity	692270	
2.5.1.22	DELTA1-19	0.003% activity compared to the wild-type enzyme	692270	
2.5.1.22	DELTA1-43	0.0002% activity compared to the wild-type enzyme	692270	
2.5.1.22	DELTA1-82	0.00023% activity compared to the wild-type enzyme	692270	
2.5.1.22	DELTA347-366	truncation of the protein at position 346 removing the last 20 residues lead to a complete loss of activity	692270	
2.5.1.22	DELTA358-366A	smaller truncation of only 9 residues has a smaller effect but still reduced activity by 75%	692270	
2.5.1.22	E353Q	1000fold decrease in ratio kcat/Km value	687717	
2.5.1.22	E353Q	mutation of Glu353 to Gln reduces the kcat/Km by 800fold	692270	
2.5.1.22	F58L	the mutation is associated with the Snyder-Robinson syndrome	738421	
2.5.1.22	G191S	the mutation at a site far away from the active pocket affects the active site dynamics and thus the functionality of SpmSyn. This suggests that SpmSyn functionality is regulated by networks of interacting residues and thus expands the functional and structural importance beyond the amino acids directly involved in the catalysis	759684	
2.5.1.22	G56S	naturally occuring missense mutation involved in Snyder-Robinson Syndrome, the mutation affects dimer and monomer stability and perturb the hydrogen bond network of the functionally important amino acids	723531	
2.5.1.22	G56S	point mutation, leads to a large loss of spermine synthase activity, an inability to form dimers	708060	
2.5.1.22	G56S	the mutation destabilizes the enzyme homodimer and thus abolishes enzymatic activity	739497	
2.5.1.22	G56S	the mutation is associated with the Snyder-Robinson syndrome	738421	
2.5.1.22	G67E	the mutation is associated with the Snyder-Robinson syndrome	738421	
2.5.1.22	I150T	naturally occuring missense mutation involved in Snyder-Robinson Syndrome, the mutation affects dimer and monomer stability and perturb the hydrogen bond network of the functionally important amino acids	723531	
2.5.1.22	I150T	point mutation, leads to a large loss of spermine synthase activity, an inability to form dimers	708060	
2.5.1.22	M35R	the mutation is associated with the Snyder-Robinson syndrome	738421	
2.5.1.22	additional information	deletion of the N-terminal domain leads to a complete loss of spermine synthase activity	687717	
2.5.1.22	additional information	enzyme is able to functionally complement spermine deficiency in yeast	689690	
2.5.1.22	additional information	enzyme null mutant, lack of spermine increases sensitivity of cells to anti-tumor agents	489877	
2.5.1.22	additional information	enzyme overexpression in transgenic mice under control of a composite CMV-IE enhancer-chicken beta-actin promotor causes no deleterious effects, the mice show normal growth, fertility, and behaviour, the content of S-adenosylmethionine in transgenic mice is important for viability, overview	657842	
2.5.1.22	additional information	mutation p.G56S in the N-terminal region of spermine synthase greatly reduces spermine synthase activity and leads to severe epilepsy and cognitive impairment related to Snyder-Robinson X-linked recessive mental retardation syndrome	688299	
2.5.1.22	additional information	the loss-of-function mutant of gene ACAULIS5 shows a severe defect in stem elongation, isolation of a T-DNA insertion mutant of gene SPMS, i.e. spms-1, showing decreased spermine levels but no obvious phenotypic alterations, an acl5-spms-1 double mutant contains no spermine but is fully viable as the wild-type and shows no phenotypic alterations under normal growth conditions, overview	658727	
2.5.1.22	additional information	yeast does not require spermine synthase since mutants in which this enzyme is deleted are viable and grow at a normal rate	708060	
2.5.1.22	P112L	the mutation is associated with the Snyder-Robinson syndrome	738421	
2.5.1.22	S165D/L175E/T178H/C206R	the mutant shows increased activity compared to the wild type enzyme	739393	
2.5.1.22	V132G	naturally occuring missense mutation involved in Snyder-Robinson Syndrome, the mutation affects dimer and monomer stability and perturb the hydrogen bond network of the functionally important amino acids	723531	
2.5.1.22	V132G	point mutation, leads to a large loss of spermine synthase activity, an inability to form dimers	708060