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sme00920                    Pathway                                

Sulfur metabolism - Sinorhizobium meliloti 1021
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.
Metabolism; Energy metabolism
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sme00920  Sulfur metabolism

Ortholog table
Other DBs
BSID: 5804
GO: 0006790
Sinorhizobium meliloti 1021 [GN:sme]
SMa2069  cysP1; ABC transporter [KO:K02048]
SM_b21133  sulfate ABC transporter substrate-binding protein [KO:K02048]
SM_b21132  sulfate ABC transporter permease [KO:K02046]
SM_b21131  sulfate ABC transporter permease [KO:K02047]
SM_b21130  sulfate ABC transporter ATP-binding protein [KO:K02045] [EC:]
SMa2067  cysA1; sulfate/thiosulfate binding protein [KO:K02045] [EC:]
SM_b21526  tauA; taurine uptake ABC transporter substrate-binding protein precursor [KO:K15551]
SM_b21528  tauC; taurine uptake ABC transporter permease [KO:K15552]
SM_b21527  tauB; taurin uptake ABC transporter ATP-binding protein [KO:K10831] [EC:]
SMc02344  periplasmic binding protein [KO:K15553]
SM_b20571  aliphatic sulfonate ABC transporter permease [KO:K15554]
SM_b20569  ABC transporter ATP-binding protein [KO:K15555] [EC:3.6.3.-]
SM_b20573  NADH-dependent FMN reductase [KO:K00299] [EC:]
SMa0857  nodQ1; adenylyl-sulfate kinase [KO:K00955] [EC:]
SM_b21224  nodQ2; adenylyl-sulfate kinase [KO:K00955] [EC:]
SMc00090  cysN; sulfate adenylyltransferase [KO:K00956] [EC:]
SMa0855  nodP1; sulfate adenylyltransferase subunit 2 [KO:K00957] [EC:]
SM_b21223  nodP2; sulfate adenylyltransferase subunit 2 [KO:K00957] [EC:]
SMc00091  cysD; sulfate adenylyltransferase [KO:K00957] [EC:]
SM_b21225  3'(2'),5'-bisphosphate nucleotidase CysQ [KO:K01082] [EC:]
SMc01952  cysQ; 3'(2'),5'-bisphosphate nucleotidase CysQ [KO:K01082] [EC:]
SMc00092  cysH; phosphoadenosine phosphosulfate reductase [KO:K00390] [EC:]
SMc04049  sulfite oxidase [KO:K00387] [EC:]
SM_b20167  hypothetical protein [KO:K17226]
SMc02124  nitrite reductase [KO:K00381] [EC:]
SMc01172  sseA; thiosulfate sulfurtransferase [KO:K01011] [EC:]
SM_b21549  thtR; sulfurtransferase [KO:K01011] [EC:]
SMc02113  cysE; serine acetyltransferase [KO:K00640] [EC:]
SMc00421  cysK1; O-acetylserine sulfhydrylase A [KO:K01738] [EC:]
SMc01174  cysK2; cysteine synthase A [KO:K01738] [EC:]
SMc03797  metA; homoserine O-succinyltransferase [KO:K00651] [EC:]
SMc02595  metB; cystathionine gamma-synthase [KO:K01739] [EC:]
SMc02217  metZ; O-succinylhomoserine sulfhydrylase [KO:K10764] [EC:2.5.1.-]
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
Grein F, Ramos AR, Venceslau SS, Pereira IA
Unifying concepts in anaerobic respiration: Insights from dissimilatory sulfur metabolism.
Biochim Biophys Acta 1827:145-60 (2013)
Fauque GD, Barton LL
Hemoproteins in dissimilatory sulfate- and sulfur-reducing prokaryotes.
Adv Microb Physiol 60:1-90 (2012)
Sakurai H, Ogawa T, Shiga M, Inoue K
Inorganic sulfur oxidizing system in green sulfur bacteria.
Photosynth Res 104:163-76 (2010)
Falkenby LG, Szymanska M, Holkenbrink C, Habicht KS, Andersen JS, Miller M, Frigaard NU
Quantitative proteomics of Chlorobaculum tepidum: insights into the sulfur metabolism of a phototrophic green sulfur bacterium.
FEMS Microbiol Lett 323:142-50 (2011)
Gregersen LH, Bryant DA, Frigaard NU
Mechanisms and evolution of oxidative sulfur metabolism in green sulfur bacteria.
Front Microbiol 2:116 (2011)
Beller HR, Chain PS, Letain TE, Chakicherla A, Larimer FW, Richardson PM, Coleman MA, Wood AP, Kelly DP.
The genome sequence of the obligately chemolithoautotrophic, facultatively anaerobic bacterium Thiobacillus denitrificans.
J Bacteriol 188:1473-88 (2006)
Pott AS, Dahl C
Sirohaem sulfite reductase and other proteins encoded by genes at the dsr locus of Chromatium vinosum are involved in the oxidation of intracellular sulfur.
Microbiology 144 ( Pt 7):1881-94 (1998)
Frigaard NU, Dahl C
Sulfur metabolism in phototrophic sulfur bacteria.
Adv Microb Physiol 54:103-200 (2009)
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