ENTRY ko00920 Pathway NAME Sulfur metabolism DESCRIPTION Sulfur is an essential element for life and the metabolism of organic sulfur compounds plays an important role in the global sulfur cycle. Sulfur occurs in various oxidation states ranging from +6 in sulfate to -2 in sulfide (H2S). Sulfate reduction can occur in both an energy consuming assimilatory pathway and an energy producing dissimilatory pathway. The assimilatory pathway, which is found in a wide range of organisms, produces reduced sulfur compounds for the biosynthesis of S-containing amino acids and does not lead to direct excretion of sulfide. In the dissimilatory pathway, which is restricted to obligatory anaerobic bacterial and archaeal lineages, sulfate (or sulfur) is the terminal electron acceptor of the respiratory chain producing large quantities of inorganic sulfide. Both pathways start from the activation of sulfate by reaction with ATP to form adenylyl sulfate (APS). In the assimilatory pathway [MD:M00176] APS is converted to 3'-phosphoadenylyl sulfate (PAPS) and then reduced to sulfite, and sulfite is further reduced to sulfide by the assimilatory sulfite reductase. In the dissimilatory pathway [MD:M00596] APS is directly reduced to sulfite, and sulfite is further reduced to sulfide by the dissimilatory sulfite reductase. The capacity for oxidation of sulfur is quite widespread among bacteria and archaea, comprising phototrophs and chemolithoautotrophs. The SOX (sulfur-oxidation) system [MD:M00595] is a well-known sulfur oxidation pathway and is found in both photosynthetic and non-photosynthetic sulfur-oxidizing bacteria. Green sulfur bacteria and purple sulfur bacteria carry out anoxygenic photosynthesis with reduced sulfur compounds such as sulfide and elemental sulfur, as well as thiosulfate (in some species with the SOX system), as the electron donor for photoautotrophic growth. In some chemolithoautotrophic sulfur oxidizers (such as Thiobacillus denitrificans), it has been suggested that dissimilatory sulfur reduction enzymes operate in the reverse direction, forming a sulfur oxidation pathway from sulfite to APS and then to sulfate. CLASS Metabolism; Energy metabolism PATHWAY_MAP ko00920 Sulfur metabolism MODULE M00021 Cysteine biosynthesis, serine => cysteine [PATH:ko00920] M00176 Assimilatory sulfate reduction, sulfate => H2S [PATH:ko00920] M00595 Thiosulfate oxidation by SOX complex, thiosulfate => sulfate [PATH:ko00920] M00596 Dissimilatory sulfate reduction, sulfate => H2S [PATH:ko00920] DBLINKS GO: 0006790 ORTHOLOGY K02048 sulfate/thiosulfate transport system substrate-binding protein K23163 sulfate/thiosulfate transport system substrate-binding protein K02046 sulfate/thiosulfate transport system permease protein K02047 sulfate/thiosulfate transport system permease protein K02045 sulfate/thiosulfate transport system ATP-binding protein [EC:7.3.2.3] K15551 taurine transport system substrate-binding protein K15552 taurine transport system permease protein K10831 taurine transport system ATP-binding protein [EC:7.6.2.7] K03119 taurine dioxygenase [EC:1.14.11.17] K15553 sulfonate transport system substrate-binding protein K15554 sulfonate transport system permease protein K15555 sulfonate transport system ATP-binding protein [EC:7.6.2.14] K04091 alkanesulfonate monooxygenase [EC:1.14.14.5 1.14.14.34] K00299 FMN reductase [EC:1.5.1.38] K13811 3'-phosphoadenosine 5'-phosphosulfate synthase [EC:2.7.7.4 2.7.1.25] K00955 bifunctional enzyme CysN/CysC [EC:2.7.7.4 2.7.1.25] K00956 sulfate adenylyltransferase subunit 1 [EC:2.7.7.4] K00957 sulfate adenylyltransferase subunit 2 [EC:2.7.7.4] K00958 sulfate adenylyltransferase [EC:2.7.7.4] K00988 sulfate adenylyltransferase (ADP) / ATP adenylyltransferase [EC:2.7.7.5 2.7.7.53] K22966 sulfate adenylyltransferase (ADP) / adenylylsulfatase [EC:2.7.7.5 3.6.2.1] K00860 adenylylsulfate kinase [EC:2.7.1.25] K01082 3'(2'), 5'-bisphosphate nucleotidase [EC:3.1.3.7] K15759 Golgi-resident PAP phosphatase [EC:3.1.3.7] K15422 3'(2'), 5'-bisphosphate nucleotidase / inositol polyphosphate 1-phosphatase [EC:3.1.3.7 3.1.3.57] K06881 bifunctional oligoribonuclease and PAP phosphatase NrnA [EC:3.1.3.7 3.1.13.3] K00394 adenylylsulfate reductase, subunit A [EC:1.8.99.2] K00395 adenylylsulfate reductase, subunit B [EC:1.8.99.2] K05907 adenylyl-sulfate reductase (glutathione) [EC:1.8.4.9] K00390 phosphoadenosine phosphosulfate reductase [EC:1.8.4.8 1.8.4.10] K00387 sulfite oxidase [EC:1.8.3.1] K05301 sulfite dehydrogenase (cytochrome) subunit A [EC:1.8.2.1] K00386 sulfite dehydrogenase (cytochrome) subunit B [EC:1.8.2.1] K21307 sulfite dehydrogenase (quinone) subunit SoeA [EC:1.8.5.6] K21308 sulfite dehydrogenase (quinone) subunit SoeB K21309 sulfite dehydrogenase (quinone) subunit SoeC K17222 L-cysteine S-thiosulfotransferase [EC:2.8.5.2] K17223 L-cysteine S-thiosulfotransferase [EC:2.8.5.2] K17226 sulfur-oxidizing protein SoxY K17227 sulfur-oxidizing protein SoxZ K17224 S-sulfosulfanyl-L-cysteine sulfohydrolase [EC:3.1.6.20] K17225 sulfane dehydrogenase subunit SoxC K22622 S-disulfanyl-L-cysteine oxidoreductase SoxD [EC:1.8.2.6] K00380 sulfite reductase (NADPH) flavoprotein alpha-component [EC:1.8.1.2] K00381 sulfite reductase (NADPH) hemoprotein beta-component [EC:1.8.1.2] K16950 anaerobic sulfite reductase subunit A K16951 anaerobic sulfite reductase subunit B K00385 anaerobic sulfite reductase subunit C K00392 sulfite reductase (ferredoxin) [EC:1.8.7.1] K11180 dissimilatory sulfite reductase alpha subunit [EC:1.8.1.22] K11181 dissimilatory sulfite reductase beta subunit [EC:1.8.1.22] K27196 dissimilatory sulfite reductase flavoprotein subunit K27187 [DsrC]-trisulfide reductase subunit M [EC:1.8.5.10] K27188 [DsrC]-trisulfide reductase subunit K [EC:1.8.5.10] K27189 [DsrC]-trisulfide reductase subunit J K27190 [DsrC]-trisulfide reductase subunit O K27191 [DsrC]-trisulfide reductase subunit P K17218 sulfide:quinone oxidoreductase [EC:1.8.5.4] K17995 sulfhydrogenase subunit gamma (sulfur reductase) [EC:1.12.98.4] K17996 sulfhydrogenase subunit beta (sulfur reductase) [EC:1.12.98.4] K17993 sulfhydrogenase subunit alpha [EC:1.12.1.3 1.12.1.5] K17994 sulfhydrogenase subunit delta [EC:1.12.1.3 1.12.1.5] K17229 sulfide dehydrogenase [flavocytochrome c] flavoprotein chain [EC:1.8.2.3] K17230 cytochrome subunit of sulfide dehydrogenase K16952 sulfur oxygenase/reductase [EC:1.13.11.55] K17219 sulfur reductase molybdopterin subunit K17220 sulfur reductase FeS subunit K17221 sulfur reductase membrane anchor K22470 eukaryotic sulfide quinone oxidoreductase [EC:1.8.5.8] K17725 sulfur dioxygenase [EC:1.13.11.18] K16936 thiosulfate dehydrogenase (quinone) small subunit [EC:1.8.5.2] K16937 thiosulfate dehydrogenase (quinone) large subunit [EC:1.8.5.2] K05908 thiosulfate dehydrogenase (quinone) [EC:1.8.5.2] K08357 tetrathionate reductase subunit A K08358 tetrathionate reductase subunit B K08359 tetrathionate reductase subunit C K08352 thiosulfate reductase / polysulfide reductase chain A [EC:1.8.5.5] K08353 thiosulfate reductase electron transport protein K08354 thiosulfate reductase cytochrome b subunit K01011 thiosulfate/3-mercaptopyruvate sulfurtransferase [EC:2.8.1.1 2.8.1.2] K02439 thiosulfate sulfurtransferase [EC:2.8.1.1] K00640 serine O-acetyltransferase [EC:2.3.1.30] K23304 serine O-acetyltransferase [EC:2.3.1.30] K10150 cysteine synthase / O-phosphoserine sulfhydrylase / cystathionine beta-synthase [EC:2.5.1.47 2.5.1.65 4.2.1.22] K01738 cysteine synthase [EC:2.5.1.47] K13034 L-3-cyanoalanine synthase/ cysteine synthase [EC:2.5.1.47 4.4.1.9] K17069 O-acetylhomoserine/O-acetylserine sulfhydrylase [EC:2.5.1.49 2.5.1.47] K00651 homoserine O-succinyltransferase/O-acetyltransferase [EC:2.3.1.46 2.3.1.31] K00641 homoserine O-acetyltransferase/O-succinyltransferase [EC:2.3.1.31 2.3.1.46] K01739 cystathionine gamma-synthase [EC:2.5.1.48] K10764 O-succinylhomoserine sulfhydrylase [EC:2.5.1.-] K17217 cystathionine gamma-lyase / homocysteine desulfhydrase [EC:4.4.1.1 4.4.1.2] K17285 methanethiol oxidase [EC:1.8.3.4] K17228 dimethylsulfone monooxygenase [EC:1.14.14.35] K16968 methanesulfonate monooxygenase subunit alpha [EC:1.14.13.111] K16969 methanesulfonate monooxygenase subunit beta [EC:1.14.13.111] K15762 toluene monooxygenase system ferredoxin subunit K15765 toluene monooxygenase electron transfer component [EC:1.18.1.3] K07306 anaerobic dimethyl sulfoxide reductase subunit A [EC:1.8.5.3] K07307 anaerobic dimethyl sulfoxide reductase subunit B K07308 anaerobic dimethyl sulfoxide reductase subunit C K00184 dimethyl sulfoxide reductase iron-sulfur subunit K00185 dimethyl sulfoxide reductase membrane subunit K16964 dimethylsulfide dehydrogenase subunit alpha [EC:1.8.2.4] K16965 dimethylsulfide dehydrogenase subunit beta K16966 dimethylsulfide dehydrogenase subunit gamma K16953 dimethylpropiothetin dethiomethylase [EC:4.4.1.3] K17486 dimethylsulfoniopropionate demethylase [EC:2.1.1.269] K20034 3-(methylthio)propionyl---CoA ligase [EC:6.2.1.44] K20035 3-(methylsulfanyl)propanoyl-CoA dehydrogenase [EC:1.3.99.41] K20036 (methylthio)acryloyl-CoA hydratase [EC:4.2.1.155] K16967 dimethyl-sulfide monooxygenase [EC:1.14.13.131] K21310 methanethiol S-methyltransferase [EC:2.1.1.334] K16954 methylthiol:coenzyme M methyltransferase [EC:2.1.1.251] K16955 methylated-thiol--corrinoid protein COMPOUND C00033 Acetate C00042 Succinate C00053 3'-Phosphoadenylyl sulfate C00054 Adenosine 3',5'-bisphosphate C00059 Sulfate C00065 L-Serine C00084 Acetaldehyde C00087 Sulfur C00094 Sulfite C00097 L-Cysteine C00155 L-Homocysteine C00224 Adenylyl sulfate C00245 Taurine C00263 L-Homoserine C00283 Hydrogen sulfide C00320 Thiosulfate C00409 Methanethiol C00580 Dimethyl sulfide C00979 O-Acetyl-L-serine C01118 O-Succinyl-L-homoserine C01861 Trithionate C02084 Tetrathionate C03920 2-(Methylthio)ethanesulfonate C04022 S,S-Dimethyl-beta-propiothetin C08276 3-(Methylthio)propanoate C11142 Dimethyl sulfone C11143 Dimethyl sulfoxide C11145 Methanesulfonic acid C15521 Alkanesulfonate C17267 S-Sulfanylglutathione C19692 Polysulfide C20870 3-(Methylthio)propanoyl-CoA C20955 3-(Methylthio)acryloyl-CoA C22834 Protein-trisulfide REFERENCE PMID:22982583 AUTHORS Grein F, Ramos AR, Venceslau SS, Pereira IA TITLE Unifying concepts in anaerobic respiration: Insights from dissimilatory sulfur metabolism. JOURNAL Biochim Biophys Acta 1827:145-60 (2013) DOI:10.1016/j.bbabio.2012.09.001 REFERENCE PMID:22633058 AUTHORS Fauque GD, Barton LL TITLE Hemoproteins in dissimilatory sulfate- and sulfur-reducing prokaryotes. JOURNAL Adv Microb Physiol 60:1-90 (2012) DOI:10.1016/B978-0-12-398264-3.00001-2 REFERENCE PMID:20143161 AUTHORS Sakurai H, Ogawa T, Shiga M, Inoue K TITLE Inorganic sulfur oxidizing system in green sulfur bacteria. JOURNAL Photosynth Res 104:163-76 (2010) DOI:10.1007/s11120-010-9531-2 REFERENCE PMID:22092713 AUTHORS Falkenby LG, Szymanska M, Holkenbrink C, Habicht KS, Andersen JS, Miller M, Frigaard NU TITLE Quantitative proteomics of Chlorobaculum tepidum: insights into the sulfur metabolism of a phototrophic green sulfur bacterium. JOURNAL FEMS Microbiol Lett 323:142-50 (2011) DOI:10.1111/j.1574-6968.2011.02370.x REFERENCE PMID:21833341 AUTHORS Gregersen LH, Bryant DA, Frigaard NU TITLE Mechanisms and evolution of oxidative sulfur metabolism in green sulfur bacteria. JOURNAL Front Microbiol 2:116 (2011) DOI:10.3389/fmicb.2011.00116 REFERENCE PMID:16452431 AUTHORS Beller HR, Chain PS, Letain TE, Chakicherla A, Larimer FW, Richardson PM, Coleman MA, Wood AP, Kelly DP. TITLE The genome sequence of the obligately chemolithoautotrophic, facultatively anaerobic bacterium Thiobacillus denitrificans. JOURNAL J Bacteriol 188:1473-88 (2006) DOI:10.1128/JB.188.4.1473-1488.2006 REFERENCE PMID:9695921 AUTHORS Pott AS, Dahl C TITLE Sirohaem sulfite reductase and other proteins encoded by genes at the dsr locus of Chromatium vinosum are involved in the oxidation of intracellular sulfur. JOURNAL Microbiology 144 ( Pt 7):1881-94 (1998) DOI:10.1099/00221287-144-7-1881 REFERENCE PMID:18929068 AUTHORS Frigaard NU, Dahl C TITLE Sulfur metabolism in phototrophic sulfur bacteria. JOURNAL Adv Microb Physiol 54:103-200 (2009) DOI:10.1016/S0065-2911(08)00002-7 REL_PATHWAY ko00260 Glycine, serine and threonine metabolism ko00270 Cysteine and methionine metabolism ko00680 Methane metabolism ko00720 Other carbon fixation pathways ///