Adenosine triphosphate-sulfurylase

Acyl carrier proteint2] Adenosine triphosphate sulfurylase (Penicillium chrysogenum)[3]... 

Molybdate is also known as an inhibitor of the important enzyme ATP sulfurylase where ATP is adenosine triphosphate, which activates sulfate for participation in biosynthetic pathways (56). The tetrahedral molybdate dianion, MoO , substitutes for the tetrahedral sulfate dianion, SO , and leads to futile cycling of the enzyme and total inhibition of sulfate activation. Molybdate is also a co-effector in the receptor for steroids (qv) in mammalian systems, a biochemical finding that may also have physiological implications (57). 

The biochemical pathway of both assimilatory and dissimilatory sulfate reduction is illustrated in Figure 1. The details of the dissimilatory reduction pathway are useful for understanding the origin of bacterial stable isotopic fractionations. The overall pathways require the transfer of eight electrons, and proceed through a number of intermediate steps. The reduction of sulfate requires activation by ATP (adenosine triphosphate) to form adenosine phosphosulfate (APS). The enzyme ATP sulfurylase catalyzes this reaction. In dissimilatory reduction, the sulfate moiety of APS is reduced to sulfite (SO3 ) by the enzyme APS reductase, whereas in assimilatory reduction APS is further phosphorylated to phospho-adenosine phosphosulfate (PAPS) before reduction to the oxidation state of sulfite and sulfide. Although the reduction reactions occur in the cell s cytoplasm (i.e., the sulfate enters the cell), the electron transport chain for dissimilatory sulfate reduction occurs in proteins that are peiiplasmic (within the bacterial cell wall). The enzyme hydrogenase... 

DNA polymerase I, Klenow Fragment, EXO(-) was obtained from Funakoshi (Tokyo, Japan). Luciferase, Adenosine-5 -triphosphate sulfurylase, adenosine 5 -phosphosulfate sodium salt, D-Luciferin sodium salt, and magnesium acetate Tetra hydrate were obtained from Sigma (MO, USA). Deoxynucleotide and 2 -deoxyadenosine 5 -0-(l-thiotriphosphate) were obtained from Amersham Pharmacia Biotech (UK). Other chemicals were of an analytical-reagent grade. Instruments ... 

PPi then triggers a cascade of enzyme-catalysed reactions (Fig. 5.28). The substrate APS reacts with the PPi and is catalysed by ATP sulfurylase, to form adenosine triphosphate (ATP). The enzyme luciferase catalyses the reaction of ATP with the substrate luciferin, generating oxyluciferin and visible light. This light can be detected by a charged coupled device (CCD) camera as a peak in a so-called pyrogram . The signal obtained is directly proportional to the amount of dNTP incorporated. 

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