Natural Variation in the ATPS1 Isoform of ATP Sulfurylase Contributes to the Control of Sulfate Levels in Arabidopsis1[W]

Natural Variation in ATPS1 Isoform of ATP Sulfurylase Contributes to Control of Sulfate Levels in Arabidopsis

Natural variation in the ATPS1 isoform of ATP sulfurylase contributes to the control of sulfate levels in Arabidopsis.

Sulfur is an essential macronutrient for all living organisms. Plants take up inorganic sulfate from the soil, reduce it, and assimilate it into bioorganic compounds, but part of this sulfate is stored in the vacuoles. In our first attempt to identify genes involved in the control of sulfate content in the leaves, we reported that a quantitative trait locus (QTL) for sulfate content in Arabidop...

Comparative Enzymology of the Adenosine Triphosphate Sulfurylases from Leaf and Swollen Hypocotyl Tissue of Beta vulgaris: Multiple Enzyme Forms in Hypocotyl Tissue.

ATP sulfurylase activity was partially purified from the swollen hypocotyl of beetroot (Beta vulgaris); activity was measured by sulfate-dependent PPi-ATP exchange. The ATP sulfurylase activity was separated from pyrophosphatase and ATPase activities which interfere with the assay of ATP sulfurylase activity. The ATP sulfurylase activity from hypocotyl tissue was invariably resolved into two ap...

Kinetic mechanism of the dimeric ATP sulfurylase from plants

In plants, sulfur must be obtained from the environment and assimilated into usable forms for metabolism. ATP sulfurylase catalyses the thermodynamically unfavourable formation of a mixed phosphosulfate anhydride in APS (adenosine 5'-phosphosulfate) from ATP and sulfate as the first committed step of sulfur assimilation in plants. In contrast to the multi-functional, allosterically regulated AT...

Assay of adenosine 5-triphosphate sulfurylase by pyrophosphate exchange.

The sulfate-dependent pyrophosphate exchange reaction has been re-examined and confirmed. Standard assay conditions for measuring ATP sulfurylase by sulfate-dependent pyrophosphate exchange are described and some properties of the enzyme (measured in crude dialyzed extracts) are reported. This method has many advantages over the well established molybdate method.