sulfate adenylyltransferase (ATP) | |||||||||
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Identifiers | |||||||||
EC no. | 2.7.7.4 | ||||||||
CAS no. | 9012-39-9 | ||||||||
Databases | |||||||||
IntEnz | IntEnz view | ||||||||
BRENDA | BRENDA entry | ||||||||
ExPASy | NiceZyme view | ||||||||
KEGG | KEGG entry | ||||||||
MetaCyc | metabolic pathway | ||||||||
PRIAM | profile | ||||||||
PDB structures | RCSB PDB PDBe PDBsum | ||||||||
Gene Ontology | AmiGO / QuickGO | ||||||||
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ATP-sulfurylase | |||||||||
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Identifiers | |||||||||
Symbol | ATP-sulfurylase | ||||||||
Pfam | PF01747 | ||||||||
InterPro | IPR002650 | ||||||||
SCOP2 | 1i2d / SCOPe / SUPFAM | ||||||||
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In enzymology, a sulfate adenylyltransferase (EC 2.7.7.4) is an enzyme that catalyzes the chemical reaction
Thus, the two substrates of this enzyme are ATP and sulfate, whereas its two products are pyrophosphate and adenylyl sulfate.
This enzyme belongs to the family of transferases, specifically those transferring phosphorus-containing nucleotide groups (nucleotidyltransferases). The systematic name of this enzyme class is ATP:sulfate adenylyltransferase. Other names in common use include adenosine-5'-triphosphate sulfurylase, adenosinetriphosphate sulfurylase, adenylylsulfate pyrophosphorylase, ATP sulfurylase, ATP-sulfurylase, and sulfurylase. This enzyme participates in 3 metabolic pathways: purine metabolism, selenoamino acid metabolism, and sulfur metabolism.
Some sulfate adenylyltransferases are part of a bifunctional polypeptide chain associated with adenosyl phosphosulfate (APS) kinase. Both enzymes are required for PAPS (phosphoadenosine-phosphosulfate) synthesis from inorganic sulfate. [1] [2]
Within the cell sulfate adenylyltransferase plays a key role in both assimilatory sulfur reduction and dissimilatory sulfur oxidation and reduction (DSR) and participates in the biogeochemically relevant sulfur cycle. [3] [4] In dissimilatory sulfate reduction the SAT enzyme, acts as the first priming step in the reduction converting sulfate (+6) to adenosine 5'-phosphosulfate (APS) via adenylation at the cost of an ATP. If the organisms participating in the DSR pathway possess the full suite of genes necessary, APS can then be further stepwise reduced to sulfite (+4) and then sulfide (-2). Conversely in the process of dissimilatory sulfur oxidation, pyrophosphate combines with APS in a sulfate adenylyltransferase catalyzed reaction to form sulfate. [3] In either direction in which the sulfate adenylyltransferase (reduction or oxidation) proceeds along DSR in bacterial cells, the associated pathways are participating in cellular respiration necessary for the growth of the organism. [5]
As of late 2007, 18 structures have been solved for this class of enzymes, with PDB accession codes 1G8F, 1G8G, 1G8H, 1I2D, 1J70, 1JEC, 1JED, 1JEE, 1JHD, 1M8P, 1R6X, 1TV6, 1V47, 1X6V, 1XJQ, 1XNJ, 1ZUN, and 2GKS.
In yeast other fungi and bacteria participating in assimilatory sulfate reduction, the sulfate adenylyltransferase is in the form a of a homohexamer. [3] [6] Its shape is that of a homotetramer in plants. [7] In Saccharomyces cerevisiae , sulfate adenylyltransferase is composed of four domains. Domain I features the N-terminus with beta-barrels similar to pyruvate kinase. A right handed alpha/beta fold makes of the shape of Domain II, and it also contains the active site and substrate-binding pocket. Domain III is composed of a region linking the terminal domain to Domain I & II. Domain IV contains the C-terminus of the protein and forms a typical alpha/beta-fold. [6] The active site of sulfate adenylyltransferase is composed mostly of portions of the Domain II specifically, H9, S9, S10, S12, and the conserved RNP-Loop and GRD-Loop. [8] The active site is located in the center of the sulfate adenylyltransferase above the Domain II between the other domains I and II. The core of the groove in which the active site is located is mostly composed of hydrophobic residues, but towards the outside of the groove are positive and hydrophilic residues necessary for substrate binding. [8]
ATP sulfurylase is one of the enzymes used in pyrosequencing.
Pyrosequencing is a method of DNA sequencing based on the "sequencing by synthesis" principle, in which the sequencing is performed by detecting the nucleotide incorporated by a DNA polymerase. Pyrosequencing relies on light detection based on a chain reaction when pyrophosphate is released. Hence, the name pyrosequencing.
Sulfate-reducing microorganisms (SRM) or sulfate-reducing prokaryotes (SRP) are a group composed of sulfate-reducing bacteria (SRB) and sulfate-reducing archaea (SRA), both of which can perform anaerobic respiration utilizing sulfate (SO2−
4) as terminal electron acceptor, reducing it to hydrogen sulfide (H2S). Therefore, these sulfidogenic microorganisms "breathe" sulfate rather than molecular oxygen (O2), which is the terminal electron acceptor reduced to water (H2O) in aerobic respiration.
Sulfur assimilation is the process by which living organisms incorporate sulfur into their biological molecules. In plants, sulfate is absorbed by the roots and then transported to the chloroplasts by the transipration stream where the sulfur are reduced to sulfide with the help of a series of enzymatic reactions. Furthermore, the reduced sulfur is incorporated into cysteine, an amino acid that is a precursor to many other sulfur-containing compounds. In animals, sulfur assimilation occurs primarily through the diet, as animals cannot produce sulfur-containing compounds directly. Sulfur is incorporated into amino acids such as cysteine and methionine, which are used to build proteins and other important molecules.
3′-Phosphoadenosine-5′-phosphosulfate (PAPS) is a derivative of adenosine monophosphate (AMP) that is phosphorylated at the 3′ position and has a sulfate group attached to the 5′ phosphate. It is the most common coenzyme in sulfotransferase reactions and hence part of sulfation pathways. It is endogenously synthesized by organisms via the phosphorylation of adenosine 5′-phosphosulfate (APS), an intermediary metabolite. In humans such reaction is performed by bifunctional 3′-phosphoadenosine 5′-phosphosulfate synthases using ATP as the phosphate donor.
Adenylyl-sulfate reductase is an enzyme that catalyzes the chemical reaction of the reduction of adenylyl-sulfate/adenosine-5'-phosphosulfate (APS) to sulfite through the use of an electron donor cofactor. The products of the reaction are AMP and sulfite, as well as an oxidized electron donor cofactor.
Adenylyl-sulfate reductase (glutathione) is an enzyme that catalyzes the chemical reaction
Adenylyl-sulfate reductase (thioredoxin) is an enzyme that catalyzes the chemical reaction
Sulfite reductases (EC 1.8.99.1) are enzymes that participate in sulfur metabolism. They catalyze the reduction of sulfite to hydrogen sulfide and water. Electrons for the reaction are provided by a dissociable molecule of either NADPH, bound flavins, or ferredoxins.
In enzymology, an adenylylsulfatase is an enzyme that catalyzes the chemical reaction
In enzymology, an adenylyl-sulfate kinase is an enzyme that catalyzes the chemical reaction
In enzymology, a sulfate adenylyltransferase (ADP) (EC 2.7.7.5) is an enzyme that catalyzes the chemical reaction
Nicotinamide mononucleotide adenylyltransferase 1 (NMNAT1) is an enzyme that in humans is encoded by the nmnat1 gene. It is a member of the nicotinamide-nucleotide adenylyltransferases (NMNATs) which catalyze nicotinamide adenine dinucleotide (NAD) synthesis.
Bifunctional 3'-phosphoadenosine 5'-phosphosulfate synthetase 1 is an enzyme that in humans is encoded by the PAPSS1 gene.
Bifunctional 3'-phosphoadenosine 5'-phosphosulfate synthetase 2 is an enzyme that in humans is encoded by the PAPSS2 gene.
Sulfur is metabolized by all organisms, from bacteria and archaea to plants and animals. Sulfur can have an oxidation state from -2 to +6 and is reduced or oxidized by a diverse range of organisms. The element is present in proteins, sulfate esters of polysaccharides, steroids, phenols, and sulfur-containing coenzymes.
Sulfate conjugates are a heterogeneous class of polar, anionic organosulfate compounds containing an ester of sulfuric acid. Sulfate conjugates commonly result from the metabolic conjugation of endogenous and exogenous compounds with sulfate (-OSO3−).
In biochemistry, carbohydrate sulfotransferases are enzymes within the class of sulfotransferases which catalyze the transfer of the sulfate functional group to carbohydrate groups in glycoproteins and glycolipids. Carbohydrates are used by cells for a wide range of functions from structural purposes to extracellular communication. Carbohydrates are suitable for such a wide variety of functions due to the diversity in structure generated from monosaccharide composition, glycosidic linkage positions, chain branching, and covalent modification. Possible covalent modifications include acetylation, methylation, phosphorylation, and sulfation. Sulfation, performed by carbohydrate sulfotransferases, generates carbohydrate sulfate esters. These sulfate esters are only located extracellularly, whether through excretion into the extracellular matrix (ECM) or by presentation on the cell surface. As extracellular compounds, sulfated carbohydrates are mediators of intercellular communication, cellular adhesion, and ECM maintenance.
Dissimilatory sulfate reduction is a form of anaerobic respiration that uses sulfate as the terminal electron acceptor to produce hydrogen sulfide. This metabolism is found in some types of bacteria and archaea which are often termed sulfate-reducing organisms. The term "dissimilatory" is used when hydrogen sulfide is produced in an anaerobic respiration process. By contrast, the term "assimilatory" would be used in relation to the biosynthesis of organosulfur compounds, even though hydrogen sulfide may be an intermediate.
Dissimilatory sulfite reductase is an enzyme that participates in sulfur metabolism in dissimilatory sulfate reduction.
Prosthecochloris aestuarii is a green sulfur bacterium in the genus Prosthecochloris. This organism was originally isolated from brackish lagoons located in Sasyk-Sivash and Sivash. They are characterized by the presence of "prosthecae" on their cell surface; the inner part of these appendages house the photosynthetic machinery within chlorosomes, which are characteristic structures of green sulfur bacteria. Additionally, like other green sulfur bacteria, they are Gram-negative, non-motile, and non-spore forming. Of the four major groups of green sulfur bacteria, P. aestuarii serves as the type species for Group 4.