Adenylylsulfate

The adenylylsulfate reductase (APS reductase, AdoPS04 reductase) catalyzes the following reversible reaction ... 

Although three different models were already proposed to explain the mechanism of adenylylsulfate reduction (141-143), a global model (taking in account the spectroscopic features discussed earlier) was not yet presented. In particular, the role of center II is still unknown. 

The scheme (Fig. 15.1) thus explained the production of both sulfate and sulfur in equimolar amounts from thiosulfate oxidation. In showing adenylylsulfate as an intermediate, it also provided a feasible route for the conservation of energy from sulfite oxidation by a substrate-level phosphorylation mechanism, in which ADP sulfurylase and adenylate kinase give rise to ATP ... 

Taylor BE 1989. Thermotolerance of adenylylsulfate reductase from Thiobacillus denitrificans. FEMS Microbiol Lett 59 351. ... 

This enzyme [EC 2.7.1.25], also referred to as APS kinase, catalyzes the reaction of ATP and adenylylsulfate to generate ADP and 3 -phosphoadenylylsulfate. 

This enzyme [EC 1.8.99.2] catalyzes the reaction of AMP, sulfite, and some acceptors (for example, methyl viologen) to yield adenylylsulfate and the reduced acceptor. Both FAD and iron are cofactors. 

This enzyme [EC 3.6.2.1], also called adenylylsulfatase, catalyzes the hydrolysis of adenylylsulfate to generate AMP and sulfate. 

This enzyme [EC 2.7.7.5], also known as ADP sulfurylase, catalyzes the reaction of ADP with sulfate to produce orthophosphate and adenylylsulfate. 

ACETATE KINASE ACETYL-CoA CARBOXYLASE ACETYL-CoA SYNTHETASE N-ACETYLCLUCOSAMINE KINASE ACTIN ATPase ACTOMYOSIN ATPase N-ACYLMANNOSAMINE KINASE ADENINE NUCLEOTIDE TRANSLOCASE ADENOSINE KINASE ADENYLATE KINASE (MYOKINASE) ADENYLYLSULFATE KINASE d-ALANINE-d-ALANINE LIGASE... 

ADENYLYLSULFATE REDUCTASE ANTHRANILATE L,2-DIOXYGENASE BENZENE L,2-DIOXYGENASE BENZOATE L,2-DIOXYGENASE CARBON MONOXIDE DEHYDROGENASE... 

Adenylylsulfate reductase (APS reductase), in sulfate-reducing bacteria, 47 382-385 Adiabaticity, porphyrins and, 32 48 ADP, arsonomethyl analogue, 44 200 Adrenodoxin, amino acid sequence, 38 239-240... 

ApoSOD, 45 186, 190 Apo VFe protein, 47 204 APS reductase, see Adenylylsulfate reductase Aqua-bridged hydroxo complexes acid-base equilibria, 32 110 of dihydroxo-bridged species, 32 114-115... 

Two [Fe4S4] clusters have been identified and analyzed in bacterial and archaeal adenylylsulfate reductases. These enzymes are of importance in the sulfur cycle. The role of the iron-sulfur centres in relation to the third cofactor, FAD, has been studied. It was shown that the [Fe4S4] clusters function were electron transport guiding two electrons to the FAD catalytic site.234 A novel [Fe4S4] cluster with a high spin ground state (S = 3/2) was observed in the catalytic site of E. coli nitrate reductase A.235... 

The first-mentioned mechanism comprises several enzymatic steps and is initiated by the enzyme adenylylsulfate (APS) reductase catalyzing the following reaction ... 

Another promising MS approach is the investigation of noncovalent complexes. A beautiful example of this was provided by Leary in a study of 5 -adenylylsulfate (APS) reductase, a 4F-4S iron—sulfur cluster-containing protein.131 APS reductase catalyzes the reduction of APS to sulfite. Leary and coworkers were able to observe... 

Fig. 4.2. The oxidation mechanisms of lactate by sulfate in the sulfate-reducing bacteria of Desulfovibrio genus. Circled numbers 1, lactate dehydrogenase (cytochrome c-553) 2, pyruvate-ferredoxin 2-oxidoreductase (CoA-acetylating) 3, phosphate acetyltransferase 4, acetate kinase 5, sulfate adenylyltransferase 6, adenylylsulfate reductase 7, sulfite reductase 8, adenylate kinase. ATP adenosine 5 -triphosphate is also biosynthesized by the catalysis of ATP synthase using the energy liberated by the electron transfer around this part...

In Fig. 4.2, the oxidation mechanisms of lactate with sulfate in the bacteria of Desulfovibrio genus is shown. In the reduction of sulfate, first the compound is changed into adenylylsulfate (APS) using ATP. APS is reduced by the catalysis of adenylylsulfate reductase to sulfite and AMP. The sulfite formed is reduced to... 

The sulfite oxidation pathway other than that mentioned above occurs in some thiobacilli sulfite reacts with AMP by the catalysis of adenylylsulfate reductase (APS reductase) to form APS and then APS reacts with diphosphate by the catalysis of sulfate adenylyltransferase to produce sulfate and ATP (Lyric and Suzuki, 1970c Stille and Triiper, 1984), or APS reacts with orthophosphate by the catalysis of sulfate adenylyltransferase (ADP) and ATP is formed from resulting ADP by the catalysis of adenylate kinase (Zimmermann et al., 1999). 

Adenylylsulfate reductase of T. thioparus with the molecular mass of 170 kDa has one molecule of FAD, 8-10 atoms of non-heme iron, and 4-5 atoms of inorganic sulfide in the molecule (Adachi and Suzuki, 1977). 

Lampreia J, Moura L, Teixeria M, Peck HD Jr, LeGall J, Huynth BH, Moura JJG (1990) The active centers of adenylylsulfate reductase from Desulfovibrio gigas. Characterization and spectroscopic studies. Eur J Biochem 188 653-664... 

Steuber J, Cypionk H, Kroneck PMH (1994) Mechanism of dissimilatory sulfite reduction by Desulfovibrio desulfuricans purification of membrane-bound sulfite reductase and coupling with cytochrome c3 and hydrogenase. Arch Microbiol 162 255-260 Stille W, Triiper HG (1984) Adenylylsulfate reductase in some new sulfate reducing bacteria. Arch Microbiol 137 145-150... 

---