2.4.2.7	D99N	mutant enzyme has very low activity	-, 724940	
2.4.2.7	E104L	site-directed mutagenesis, the mutation decreases the catalytic efficiency of the enzyme in the forward reaction	759017	
2.4.2.7	E106L	site-directed mutagenesis, decreased turnover, increased Km value for adenine and decreased Km value for 5-phosphoribose 1-phosphate compared to the wild-type	638171	
2.4.2.7	E106L	site-directed mutagenesis, the mutant shows highly reduced kcat compared to wild-type	-, 758562	
2.4.2.7	E106Q	site-directed mutagenesis, decreased turnover and Km value for 5-phosphoribose 1-phosphate compared to the wild-type	638171	
2.4.2.7	F23A	site-directed mutagenesis, the mutation on the base-binding loop severely affects the activity and efficiency of the enzyme, the mutant enzyme is about 200fold less active as compared with wild-type	-, 759176	
2.4.2.7	F25W	site-directed mutagenesis, tryptophan at the adenine binding site, kinetic constants similar to the wild-type	638167	
2.4.2.7	G108A	site-directed mutagenesis, increased Km value for adenine and 5-phosphoribose 1-phosphate compared to the wild-type	638171	
2.4.2.7	G108H	site-directed mutagenesis, decreased turnover, slightly increased Km value for adenine and 5-phosphoribose 1-phosphate compared to the wild-type	638171	
2.4.2.7	G133D	mutation in adenine phosphoribosyltransferase gene in patients with 2,8-dihydroxyadenine urolithiasis, Japanese patient	660036	
2.4.2.7	G168E	the mutant of isoform APT1 shows reduced activity with zeatin (about 14%) and adenine (about 28%), respectively, compared to the wild type enzyme	736843	
2.4.2.7	G195D	the mutant of isoform APT1 shows nearly no activity with zeatin and adenine, respectively, compared to the wild type enzyme	736843	
2.4.2.7	G196R	the mutant of isoform APT1 shows nearly no activity with zeatin and adenine, respectively, compared to the wild type enzyme	736843	
2.4.2.7	K90A	site-directed mutagenesis, decreased turnover compared to the wild-type	638171	
2.4.2.7	K93A	site-directed mutagenesis, decreased turnover, increased Km value for adenine and 5-phosphoribose 1-phosphate compared to the wild-type	638171	
2.4.2.7	L110P	mutation is associated with renal dysfunction	658879	
2.4.2.7	L96F	the mutant of isoform APT1 shows reduced activity with zeatin (about 11%) and adenine (about 8%), respectively, compared to the wild type enzyme	736843	
2.4.2.7	M136T	10.3% loss of activity	659576	
2.4.2.7	additional information	a naturally occuring mutation T596G leading to amino acid exchange F199C in hypoxanthine guanine phosphoribosyltransferase, HPRT, EC 2.4.2.8, with 92% reduced activity and a severe gouty arthritis phenotype, while the mutation or HPRT deficiency typically lead to a 2-3fold increased APRT activity in erythrocytes. Modeling of the mutated protein for prediction of the mechanisms of partial enzymatic activity	701979	
2.4.2.7	additional information	alignment of amino acid sequences, correlation between human clinical missense mutations and structure, structure taken from Leishmania donovani enzyme	638166	
2.4.2.7	additional information	antisense expression of the enzyme for opression of the APT2 gene in Arabidopsis thaliana leads to lower AMP content, lower pollen germination rates, and some abnormalities in leaf phenotypes and flowering timing in the transgenic plants, overview	676537	
2.4.2.7	additional information	construction of an aprth knockout strain (Tt27DELTAAPRTh) and an aprth-overexpressing strain (Tt27NStHisAPRTh) of Thermus thermophilus in minimal medium. The Tt27DELTAAPRTh strain exhibits delayed growth and requires approximately 36 h to reach the early stationary phase, whereas the wild-type strain reached this phase after 21 h of cultivation. The Tt27NStHisAPRTh strain exhibits better growth than even the wild-type strain	-, 759432	
2.4.2.7	additional information	covalent immobilization of TtAPRT2 through surface exposed Lys residues promotes a multipoint covalent attachment which leads to higher degree of rigidification, thereby increasing the thermal stability of the protein. Dimeric TtAPRT2 is immobilized onto glutaraldehyde-activated magnetic iron oxide porous microparticles by two different strategies: (a) an enzyme immobilization at pH 8.5 to encourage the immobilization process by N-termini (MTtAPRT2A, MTtAPRT2B, MTtAPRT2C) or (b) an enzyme immobilization at pH 10.0 to encourage the immobilization process through surface exposed lysine residues (MTtAPRT2D, MTtAPRT2E, MTtAPRT2F). According to catalyst load experiments, MTtAPRT2B (activity: 480 IU/g biocatalyst, activity recovery 52%) and MTtAPRT2F (activity 507 IU/g biocatalyst, activity recovery 44%) are chosen as optimal derivatives. The potential reusability of MTtAPRT2B and MTtAPRT2F is also tested. Finally, MTtAPRT2F is employed in the synthesis of nucleoside-5'-monophosphate analogues. 0.025 ml of the bead suspension (0.020 mg/ml) are washed and equilibrated in corresponding binding buffer containing 50 mM potassium phosphate buffer, pH 8.5, 50 mM sodium borate buffer, pH 10.0, or 50 mM sodium borate buffer, pH 10.6, during 4 h at 25°C	-, 758925	
2.4.2.7	additional information	determination and phenotype analysis of a naturally occuring mutation in the APRT gene by a homozygous 254 bp deletion-8 bp insertion mutation in exon 3, the patients shows sever renal failure, with pathological presence of adenine in both biological fluids, urinary stone excretion, and no enzyme activityin the hemolysate, overview	673115	
2.4.2.7	additional information	heterozygotes for the 254 bp deletion-8 bp insertion of the APRT gene show a 69% lower APRT enzymatic activity	673115	
2.4.2.7	additional information	identification of three cases of APRT*Q0 /APRT*J compound heterozygote-type APRT deficiency, genotyping, overview	706077	
2.4.2.7	additional information	Saccharomyces cerevisiae strain DS1-2b expressing the Tyr105Phe variant of hAPRT displays a reduced growth rate in absence of exogenous adenine, similar to the Glu104Leu variant, compared with the wild-type	759017	
2.4.2.7	P85T	the mutant of isoform APT1 shows nearly no activity with zeatin and adenine, respectively, compared to the wild type enzyme	736843	
2.4.2.7	R149K	the mutant of isoform APT1 shows no activity with zeatin and adenine, respectively, compared to the wild type enzyme	736843	
2.4.2.7	R67Q	mutation in adenine phosphoribosyltransferase gene in patients with 2,8-dihydroxyadenine urolithiasis, Japanese patient	660036	
2.4.2.7	R69A	site-directed mutagenesis, decreased turnover, increased Km value for adenine compared to the wild-type	638171	
2.4.2.7	R89A	site-directed mutagenesis, decreased turnover, increased Km value for adenine and 5-phosphoribose 1-phosphate compared to the wild-type	638171	
2.4.2.7	V84W	mutation in adenine phosphoribosyltransferase gene in patients with 2,8-dihydroxyadenine urolithiasis, Japanese patient	660036	
2.4.2.7	Y103F	site-directed mutagenesis, increased turnover, increased Km value for adenine and 5-phosphoribose 1-phosphate compared to the wild-type	638171	
2.4.2.7	Y105F	site-directed mutagenesis, the mutation increases the inhibitory effect of AMP while decreasing the catalytic efficiency of the enzyme in the forward reaction	759017	
2.4.2.7	Y107D	site-directed mutagenesis, decreased turnover, increased Km value for adenine compared to the wild-type	638171	
2.4.2.7	Y107F	site-directed mutagenesis, decreased turnover, increased Km value for adenine and 5-phosphoribose 1-phosphate compared to the wild-type	638171