KEGG   PATHWAY: gmx00230
Entry
gmx00230                    Pathway                                
Name
Purine metabolism - Glycine max (soybean)
Class
Metabolism; Nucleotide metabolism
Pathway map
gmx00230  Purine metabolism
gmx00230

Module
gmx_M00005  PRPP biosynthesis, ribose 5P => PRPP [PATH:gmx00230]
gmx_M00048  De novo purine biosynthesis, PRPP + glutamine => IMP [PATH:gmx00230]
gmx_M00049  Adenine ribonucleotide biosynthesis, IMP => ADP,ATP [PATH:gmx00230]
gmx_M00050  Guanine ribonucleotide biosynthesis, IMP => GDP,GTP [PATH:gmx00230]
gmx_M00053  Deoxyribonucleotide biosynthesis, ADP/GDP/CDP/UDP => dATP/dGTP/dCTP/dUTP [PATH:gmx00230]
Other DBs
GO: 0006163 0042278
Organism
Glycine max (soybean) [GN:gmx]
Gene
100792911  manganese-dependent ADP-ribose/CDP-alcohol diphosphatase [KO:K01517] [EC:3.6.1.13 3.6.1.16 3.6.1.53]
100780293  manganese-dependent ADP-ribose/CDP-alcohol diphosphatase [KO:K01517] [EC:3.6.1.13 3.6.1.16 3.6.1.53]
100808714  manganese-dependent ADP-ribose/CDP-alcohol diphosphatase [KO:K01517] [EC:3.6.1.13 3.6.1.16 3.6.1.53]
100815255  manganese-dependent ADP-ribose/CDP-alcohol diphosphatase [KO:K01517] [EC:3.6.1.13 3.6.1.16 3.6.1.53]
100783941  nudix hydrolase 10 isoform X3 [KO:K26956] [EC:3.6.1.13 3.6.1.22]
106795478  nudix hydrolase 2 [KO:K26956] [EC:3.6.1.13 3.6.1.22]
100819062  nudix hydrolase 2 [KO:K26956] [EC:3.6.1.13 3.6.1.22]
100818821  nudix hydrolase 2 isoform X1 [KO:K26956] [EC:3.6.1.13 3.6.1.22]
100810351  nudix hydrolase 10 [KO:K26956] [EC:3.6.1.13 3.6.1.22]
100801176  nudix hydrolase 2 [KO:K26956] [EC:3.6.1.13 3.6.1.22]
100778567  nudix hydrolase 2 [KO:K26956] [EC:3.6.1.13 3.6.1.22]
100777180  nudix hydrolase 23, chloroplastic isoform X2 [KO:K18453] [EC:3.6.1.13 3.6.1.18]
100783108  nudix hydrolase 23, chloroplastic isoform X1 [KO:K18453] [EC:3.6.1.13 3.6.1.18]
100808417  nudix hydrolase 23, chloroplastic [KO:K18453] [EC:3.6.1.13 3.6.1.18]
100809537  nudix hydrolase 14, chloroplastic [KO:K18447] [EC:3.6.1.21]
100818255  nudix hydrolase 14, chloroplastic [KO:K18447] [EC:3.6.1.21]
100780166  phosphoglucomutase, cytoplasmic [KO:K01835] [EC:5.4.2.2]
100802730  phosphoglucomutase, chloroplastic [KO:K01835] [EC:5.4.2.2]
100778321  phosphoglucomutase, chloroplastic isoform X1 [KO:K01835] [EC:5.4.2.2]
100802789  phosphoglucomutase, cytoplasmic [KO:K01835] [EC:5.4.2.2]
100816430  ribose-phosphate pyrophosphokinase 1 isoform X2 [KO:K00948] [EC:2.7.6.1]
100789585  ribose-phosphate pyrophosphokinase 1 isoform X1 [KO:K00948] [EC:2.7.6.1]
100794730  ribose-phosphate pyrophosphokinase 1 isoform X2 [KO:K00948] [EC:2.7.6.1]
100807743  ribose-phosphate pyrophosphokinase 1 [KO:K00948] [EC:2.7.6.1]
548065  PUR1; amidophosphoribosyltransferase, chloroplastic [KO:K00764] [EC:2.4.2.14]
100801720  amidophosphoribosyltransferase 1 [KO:K00764] [EC:2.4.2.14]
100791919  amidophosphoribosyltransferase, chloroplastic [KO:K00764] [EC:2.4.2.14]
100797730  amidophosphoribosyltransferase, chloroplastic [KO:K00764] [EC:2.4.2.14]
547987  PURD; phosphoribosylamine--glycine ligase [KO:K01945] [EC:6.3.4.13]
548052  PUR3; phosphoribosylglycinamide formyltransferase, chloroplastic [KO:K00601] [EC:2.1.2.2]
100784486  phosphoribosylglycinamide formyltransferase, chloroplastic [KO:K00601] [EC:2.1.2.2]
100818572  probable phosphoribosylformylglycinamidine synthase, chloroplastic/mitochondrial [KO:K01952] [EC:6.3.5.3]
100794589  probable phosphoribosylformylglycinamidine synthase, chloroplastic/mitochondrial [KO:K01952] [EC:6.3.5.3]
100817607  phosphoribosylformylglycinamidine cyclo-ligase, chloroplastic/mitochondrial [KO:K01933] [EC:6.3.3.1]
100790263  phosphoribosylformylglycinamidine cyclo-ligase, chloroplastic/mitochondrial [KO:K01933] [EC:6.3.3.1]
100787182  phosphoribosylaminoimidazole carboxylase, chloroplastic isoform X1 [KO:K11808] [EC:4.1.1.21]
100812377  phosphoribosylaminoimidazole carboxylase, chloroplastic isoform X1 [KO:K11808] [EC:4.1.1.21]
100801209  phosphoribosylaminoimidazole-succinocarboxamide synthase, chloroplastic [KO:K01923] [EC:6.3.2.6]
100805369  phosphoribosylaminoimidazole-succinocarboxamide synthase, chloroplastic [KO:K01923] [EC:6.3.2.6]
100818533  adenylosuccinate lyase [KO:K01756] [EC:4.3.2.2]
100801575  adenylosuccinate lyase [KO:K01756] [EC:4.3.2.2]
100780790  bifunctional purine biosynthesis protein PurH [KO:K00602] [EC:2.1.2.3 3.5.4.10]
100780260  bifunctional purine biosynthesis protein PurH [KO:K00602] [EC:2.1.2.3 3.5.4.10]
100306411  adenine phosphoribosyl transferase [KO:K00759] [EC:2.4.2.7]
100499904  uncharacterized protein LOC100499904 [KO:K00759] [EC:2.4.2.7]
100777103  adenine phosphoribosyltransferase 1 [KO:K00759] [EC:2.4.2.7]
100790431  adenine phosphoribosyltransferase 4 [KO:K00759] [EC:2.4.2.7]
100810609  uncharacterized protein LOC100810609 [KO:K00759] [EC:2.4.2.7]
100775389  adenine phosphoribosyltransferase 5 isoform X2 [KO:K00759] [EC:2.4.2.7]
100818276  adenine phosphoribosyltransferase 5 isoform X3 [KO:K00759] [EC:2.4.2.7]
100526858  uncharacterized protein LOC100526858 [KO:K00759] [EC:2.4.2.7]
100305792  uncharacterized protein LOC100305792 [KO:K00759] [EC:2.4.2.7]
100791569  adenine phosphoribosyltransferase 4 isoform X1 [KO:K00759] [EC:2.4.2.7]
100808698  5'-nucleotidase SurE isoform X1 [KO:K03787] [EC:3.1.3.5 3.1.3.6]
100814744  5'-nucleotidase SurE [KO:K03787] [EC:3.1.3.5 3.1.3.6]
100776267  5'-nucleotidase SurE [KO:K03787] [EC:3.1.3.5 3.1.3.6]
100779772  uncharacterized protein LOC100779772 [KO:K03787] [EC:3.1.3.5 3.1.3.6]
100785738  5'-nucleotidase SurE isoform X1 [KO:K03787] [EC:3.1.3.5 3.1.3.6]
100790833  5'-nucleotidase SurE isoform X1 [KO:K03787] [EC:3.1.3.5 3.1.3.6]
100792340  5'-nucleotidase SurE isoform X1 [KO:K03787] [EC:3.1.3.5 3.1.3.6]
100037484  hypoxanthine-guanine phosphoribosyltransferase-like [KO:K00760] [EC:2.4.2.8]
100797406  hypoxanthine-guanine phosphoribosyltransferase [KO:K00760] [EC:2.4.2.8]
547665  IMPDH1; inosine monophosphate dehydrogenase [KO:K00088] [EC:1.1.1.205]
547628  inosine-5'-monophosphate dehydrogenase [KO:K00088] [EC:1.1.1.205]
547870  nucleoside diphosphate kinase 1 [KO:K00940] [EC:2.7.4.6]
100527141  NDPk domain-containing protein [KO:K00940] [EC:2.7.4.6]
100527475  uncharacterized protein LOC100527475 [KO:K00940] [EC:2.7.4.6]
547709  nucleoside diphosphate kinase [KO:K00940] [EC:2.7.4.6]
100500478  nucleoside diphosphate kinase 2, chloroplastic [KO:K00940] [EC:2.7.4.6]
100811753  uncharacterized protein LOC100811753 [KO:K00940] [EC:2.7.4.6]
100799934  nucleoside diphosphate kinase 2, chloroplastic [KO:K00940] [EC:2.7.4.6]
100786376  nucleoside diphosphate kinase 2, chloroplastic [KO:K00940] [EC:2.7.4.6]
100807287  probable apyrase 6 isoform X1 [KO:K01510] [EC:3.6.1.5]
100780748  LOW QUALITY PROTEIN: probable apyrase 6 [KO:K01510] [EC:3.6.1.5]
102665764  probable apyrase 6 isoform X1 [KO:K01510] [EC:3.6.1.5]
100806446  probable apyrase 6 [KO:K01510] [EC:3.6.1.5]
100786073  apyrase 2 [KO:K14641] [EC:3.6.1.5]
100804818  apyrase 1 [KO:K14641] [EC:3.6.1.5]
100787491  apyrase 2 [KO:K14641] [EC:3.6.1.5]
100784833  nucleoside-triphosphatase [KO:K14641] [EC:3.6.1.5]
100781628  GS52; ecto-apyrase GS52 precursor [KO:K14641] [EC:3.6.1.5]
100811625  apyrase 2 [KO:K14641] [EC:3.6.1.5]
100808776  uncharacterized protein LOC100808776 [KO:K01519] [EC:3.6.1.66]
100782385  inosine triphosphate pyrophosphatase [KO:K01519] [EC:3.6.1.66]
100800309  xanthine dehydrogenase 1 isoform X1 [KO:K00106] [EC:1.17.1.4 1.17.3.2]
100816689  xanthine dehydrogenase 1 isoform X1 [KO:K00106] [EC:1.17.1.4 1.17.3.2]
100790864  nudix hydrolase 25 [KO:K26955] [EC:3.6.1.17]
100306071  uncharacterized protein LOC100306071 [KO:K26955] [EC:3.6.1.17]
100794993  GMP synthase [glutamine-hydrolyzing] [KO:K01951] [EC:6.3.5.2]
100812448  GMP synthase [glutamine-hydrolyzing] [KO:K01951] [EC:6.3.5.2]
100809808  guanylate kinase 2 isoform X1 [KO:K00942] [EC:2.7.4.8]
100808931  guanylate kinase 1 [KO:K00942] [EC:2.7.4.8]
100814541  guanylate kinase 3, chloroplastic [KO:K00942] [EC:2.7.4.8]
100781406  guanylate kinase 3, chloroplastic [KO:K00942] [EC:2.7.4.8]
100527163  guanylate kinase 1 isoform X1 [KO:K00942] [EC:2.7.4.8]
100812658  guanylate kinase 2 [KO:K00942] [EC:2.7.4.8]
547948  ribonucleotide reductase large subunit B [KO:K10807] [EC:1.17.4.1]
548020  ribonucleoside-diphosphate reductase large subunit [KO:K10807] [EC:1.17.4.1]
100791639  ribonucleoside-diphosphate reductase large subunit [KO:K10807] [EC:1.17.4.1]
547521  ribonucleotide reductase small subunit [KO:K10808] [EC:1.17.4.1]
100779885  ribonucleoside-diphosphate reductase small chain [KO:K10808] [EC:1.17.4.1]
100820622  ribonucleoside-diphosphate reductase small chain [KO:K10808] [EC:1.17.4.1]
100790224  ribonucleoside-diphosphate reductase small chain [KO:K10808] [EC:1.17.4.1]
100789619  5'-deoxynucleotidase hdd1 [KO:K07023] [EC:3.1.3.89]
100784513  5'-deoxynucleotidase hdd1 isoform X1 [KO:K07023] [EC:3.1.3.89]
100798792  5'-deoxynucleotidase HDDC2 [KO:K07023] [EC:3.1.3.89]
100819398  5'-deoxynucleotidase HDDC2 isoform X2 [KO:K07023] [EC:3.1.3.89]
100802064  exopolyphosphatase PRUNE1 isoform X1 [KO:K01514] [EC:3.6.1.11]
100786637  putative GTP diphosphokinase RSH1, chloroplastic isoform X1 [KO:K00951] [EC:2.7.6.5]
100789399  probable GTP diphosphokinase RSH2, chloroplastic [KO:K00951] [EC:2.7.6.5]
100778006  probable GTP diphosphokinase CRSH, chloroplastic [KO:K00951] [EC:2.7.6.5]
100787301  probable GTP diphosphokinase RSH2, chloroplastic [KO:K00951] [EC:2.7.6.5]
100814134  putative GTP diphosphokinase RSH1, chloroplastic isoform X1 [KO:K00951] [EC:2.7.6.5]
100811618  adenylosuccinate synthetase 2, chloroplastic [KO:K01939] [EC:6.3.4.4]
100792329  adenylosuccinate synthetase 2, chloroplastic [KO:K01939] [EC:6.3.4.4]
100793831  probable AMP deaminase [KO:K01490] [EC:3.5.4.6]
100786290  AMP deaminase [KO:K01490] [EC:3.5.4.6]
100789965  AMP deaminase [KO:K01490] [EC:3.5.4.6]
100789494  adenosine kinase 2 [KO:K00856] [EC:2.7.1.20]
100780391  uncharacterized protein LOC100780391 [KO:K00856] [EC:2.7.1.20]
100801737  uncharacterized protein LOC100801737 [KO:K00856] [EC:2.7.1.20]
100810561  adenosine kinase 2-like [KO:K00856] [EC:2.7.1.20]
100818561  adenylate kinase 1, chloroplastic [KO:K00939] [EC:2.7.4.3]
100779881  probable adenylate kinase 1, chloroplastic [KO:K00939] [EC:2.7.4.3]
100790268  adenylate kinase 4 [KO:K00939] [EC:2.7.4.3]
100791848  adenylate kinase 4 [KO:K00939] [EC:2.7.4.3]
100796331  adenylate kinase 5, chloroplastic isoform X1 [KO:K00939] [EC:2.7.4.3]
100784319  uncharacterized protein LOC100784319 [KO:K00939] [EC:2.7.4.3]
100784111  probable adenylate kinase 7, mitochondrial [KO:K00939] [EC:2.7.4.3]
100777619  probable adenylate kinase 1, chloroplastic [KO:K00939] [EC:2.7.4.3]
102666238  adenylate kinase 1, chloroplastic [KO:K00939] [EC:2.7.4.3]
100814972  adenylate kinase 4 [KO:K00939] [EC:2.7.4.3]
100784021  probable adenylate kinase 7, mitochondrial [KO:K00939] [EC:2.7.4.3]
100818830  adenylate kinase 5, chloroplastic isoform X1 [KO:K00939] [EC:2.7.4.3]
100810701  adenylate kinase isoenzyme 6 homolog [KO:K18532] [EC:2.7.4.3]
100306226  putative adenylate kinase [KO:K18532] [EC:2.7.4.3]
100527302  uncharacterized protein LOC100527302 [KO:K06928] [EC:3.6.1.15]
100789438  ectonucleotide pyrophosphatase/phosphodiesterase family member 3 [KO:K01513] [EC:3.1.4.1 3.6.1.9]
100793652  uncharacterized protein LOC100793652 [KO:K01513] [EC:3.1.4.1 3.6.1.9]
100800630  venom phosphodiesterase 2 [KO:K01513] [EC:3.1.4.1 3.6.1.9]
100305764  HIT-like superfamily protein [KO:K01522] [EC:3.6.1.29]
100527670  HIT-like superfamily protein [KO:K01522] [EC:3.6.1.29]
100798834  bifunctional bis(5'-adenosyl)-triphosphatase/adenylylsulfatase FHIT [KO:K01522] [EC:3.6.1.29]
547634  ATP sulfurylase [KO:K13811] [EC:2.7.7.4 2.7.1.25]
100817530  ATP sulfurylase 1, chloroplastic [KO:K13811] [EC:2.7.7.4 2.7.1.25]
100805275  ATP sulfurylase 2 [KO:K13811] [EC:2.7.7.4 2.7.1.25]
100500116  adenyl sulfate kinase 1-like protein isoform 2 [KO:K00860] [EC:2.7.1.25]
100786331  uncharacterized protein LOC100786331 [KO:K00860] [EC:2.7.1.25]
100777457  adenylyl-sulfate kinase 3 isoform X2 [KO:K00860] [EC:2.7.1.25]
100809609  adenylyl-sulfate kinase, chloroplastic [KO:K00860] [EC:2.7.1.25]
100794000  adenylyl-sulfate kinase 3 [KO:K00860] [EC:2.7.1.25]
100793200  adenylyl-sulfate kinase 3 [KO:K00860] [EC:2.7.1.25]
100037445  UR2; uricase-2 isozyme 2 [KO:K00365] [EC:1.7.3.3]
547453  UR9; uricase-2 isozyme 1 [KO:K00365] [EC:1.7.3.3]
100805930  uric acid degradation bifunctional protein TTL-like isoform 1 [KO:K13484] [EC:3.5.2.17 4.1.1.97]
100788368  putative transthyretin-like S-allantoin synthase isoform 1 [KO:K13484] [EC:3.5.2.17 4.1.1.97]
100803592  cyanidin 3-O-glucoside 5-O-glucosyltransferase (acyl-glucose) [KO:K19964] [EC:3.5.2.17]
100792223  hydroxyisourate hydrolase [KO:K19964] [EC:3.5.2.17]
547954  HIUHase; hydroxyisourate hydrolase precursor [KO:K19964] [EC:3.5.2.17]
100804122  hydroxyisourate hydrolase [KO:K19964] [EC:3.5.2.17]
100809727  allantoinase [KO:K01466] [EC:3.5.2.5]
100810258  allantoinase [KO:K01466] [EC:3.5.2.5]
100795029  allantoinase [KO:K01466] [EC:3.5.2.5]
100796088  allantoinase isoform X1 [KO:K01466] [EC:3.5.2.5]
100137075  AAH; allantoate deiminase 1 isoform 1 precursor [KO:K02083] [EC:3.5.3.9]
100819399  AAH2; allantoate deiminase 2 precursor [KO:K02083] [EC:3.5.3.9]
100800098  (S)-ureidoglycine aminohydrolase isoform X2 [KO:K14977] [EC:3.5.3.26]
100781644  (S)-ureidoglycine aminohydrolase [KO:K14977] [EC:3.5.3.26]
100797579  putative ureidoglycolate amidohydrolase precursor [KO:K18151] [EC:3.5.1.116]
547672  URE; urease [KO:K01427] [EC:3.5.1.5]
547716  EU4; urease [KO:K01427] [EC:3.5.1.5]
Compound
C00002  ATP
C00008  ADP
C00011  CO2
C00014  Ammonia
C00020  AMP
C00035  GDP
C00037  Glycine
C00039  DNA
C00044  GTP
C00046  RNA
C00048  Glyoxylate
C00053  3'-Phosphoadenylyl sulfate
C00054  Adenosine 3',5'-bisphosphate
C00059  Sulfate
C00064  L-Glutamine
C00081  ITP
C00086  Urea
C00104  IDP
C00117  D-Ribose 5-phosphate
C00119  5-Phospho-alpha-D-ribose 1-diphosphate
C00130  IMP
C00131  dATP
C00144  GMP
C00147  Adenine
C00169  Carbamoyl phosphate
C00206  dADP
C00209  Oxalate
C00212  Adenosine
C00224  Adenylyl sulfate
C00242  Guanine
C00262  Hypoxanthine
C00286  dGTP
C00288  HCO3-
C00294  Inosine
C00301  ADP-ribose
C00330  Deoxyguanosine
C00360  dAMP
C00361  dGDP
C00362  dGMP
C00366  Urate
C00385  Xanthine
C00387  Guanosine
C00499  Allantoate
C00559  Deoxyadenosine
C00575  3',5'-Cyclic AMP
C00603  (S)-Ureidoglycolate
C00620  alpha-D-Ribose 1-phosphate
C00655  Xanthosine 5'-phosphate
C00700  XTP
C00802  Oxalureate
C00942  3',5'-Cyclic GMP
C01228  Guanosine 3',5'-bis(diphosphate)
C01260  P1,P4-Bis(5'-adenosyl)tetraphosphate
C01261  P1,P4-Bis(5'-guanosyl) tetraphosphate
C01344  dIDP
C01345  dITP
C01367  3'-AMP
C01444  Oxamate
C01762  Xanthosine
C02091  (S)-Ureidoglycine
C02348  (R)(-)-Allantoin
C02350  (S)-Allantoin
C02353  2',3'-Cyclic AMP
C02718  N-Formiminoglycine
C03090  5-Phosphoribosylamine
C03373  Aminoimidazole ribotide
C03483  Adenosine tetraphosphate
C03614  Inosine 5'-tetraphosphate
C03794  N6-(1,2-Dicarboxyethyl)-AMP
C03838  5'-Phosphoribosylglycinamide
C04051  5-Amino-4-imidazolecarboxyamide
C04376  5'-Phosphoribosyl-N-formylglycinamide
C04392  P1,P4-Bis(5'-xanthosyl) tetraphosphate
C04494  Guanosine 3'-diphosphate 5'-triphosphate
C04640  2-(Formamido)-N1-(5'-phosphoribosyl)acetamidine
C04677  1-(5'-Phosphoribosyl)-5-amino-4-imidazolecarboxamide
C04734  1-(5'-Phosphoribosyl)-5-formamido-4-imidazolecarboxamide
C04751  1-(5-Phospho-D-ribosyl)-5-amino-4-imidazolecarboxylate
C04823  1-(5'-Phosphoribosyl)-5-amino-4-(N-succinocarboxamide)-imidazole
C05239  5-Aminoimidazole
C05512  Deoxyinosine
C05513  Urate-3-ribonucleoside
C05515  5-Ureido-4-imidazole carboxylate
C05516  5-Amino-4-imidazole carboxylate
C05993  Acetyl adenylate
C06193  Guanosine 3'-phosphate
C06194  2',3'-Cyclic GMP
C06195  Imidazolone
C06196  2'-Deoxyinosine 5'-phosphate
C06197  P1,P3-Bis(5'-adenosyl) triphosphate
C06433  5'-Benzoylphosphoadenosine
C06435  5'-Butyrylphosphoinosine
C11821  5-Hydroxyisourate
C12248  5-Hydroxy-2-oxo-4-ureido-2,5-dihydro-1H-imidazole-5-carboxylate
C15667  5-Carboxyamino-1-(5-phospho-D-ribosyl)imidazole
C22395  N6-Succino-2-amino-2'-deoxyadenylate
C22441  dZMP
C22442  dZDP
C22443  dZTP
C22499  8-Hydroxyadenine
C22500  2,8-Dihydroxyadenine
Reference
PMID:10601204
  Authors
Cusa E, Obradors N, Baldoma L, Badia J, Aguilar J.
  Title
Genetic analysis of a chromosomal region containing genes required for assimilation of allantoin nitrogen and linked glyoxylate metabolism in Escherichia coli.
  Journal
J Bacteriol 181:7479-84 (1999)
DOI:10.1128/JB.181.24.7479-7484.1999
Reference
PMID:10986234
  Authors
Xi H, Schneider BL, Reitzer L.
  Title
Purine catabolism in Escherichia coli and function of xanthine dehydrogenase in purine salvage.
  Journal
J Bacteriol 182:5332-41 (2000)
DOI:10.1128/JB.182.19.5332-5341.2000
Related
pathway
gmx00030  Pentose phosphate pathway
gmx00220  Arginine biosynthesis
gmx00250  Alanine, aspartate and glutamate metabolism
gmx00260  Glycine, serine and threonine metabolism
gmx00340  Histidine metabolism
gmx00630  Glyoxylate and dicarboxylate metabolism
gmx00730  Thiamine metabolism
gmx00740  Riboflavin metabolism
gmx00790  Folate biosynthesis
KO pathway
ko00230   
LinkDB

DBGET integrated database retrieval system