Photosynthetic Sulphate Reduction

Jens D. Schwenn
1994 Zeitschrift für Naturforschung C - A Journal of Biosciences  
Plants assimilate inorganic sulphate for the bio synthesis of sulphur containing compounds. The enzymes required for reduction are found pre dominantly in the plastids which provide the necessary energy and the reductants. Sulphate re duction like nitrate or carbon dioxide assimilation is endergonic; for comparison, N 0 3 reduction to ammonia requires +347 kJ m ol-1 and C 0 2 re duction +478 kJ m ol-1 (Thauer et al., 1977) . About twice as much energy is necessary to assimilate sulphate under
more » ... te sulphate under aerobic conditions: SO I" + [8 H] + 2 H + -> H2S + 4 H 2 0 . AG 0 = +733 kJ m ol-1. SO 4 + 2 ATP + thiored + 6 Fdred + [6 H +] + O-ASer -> cysteine + acetate + A D P + PAP + 2 P; + thioox + 6 Fdox + 3 H zO -in the APS-bound sulphite reaction pathway: 0939-5075/94/0900-0531 $ 06.00 © 1994 Verlag der Zeitschrift für Naturforschung. A ll rights reserved. Unauthenticated Download Date | 2/26/20 7:55 AM 2-PP. GSH-APS © GSSO , AMP SULPH IDE INSERTION O -A S e r-----(0 p ------► Acetate cysteine 0 -A S e r-----(0 2 .ĉ ysteine Acetate GSH Aketagawa A cD N A for adenylyl sulphate (APS) kinase from A rabidopsis thaliana. Biochim. Biophys. A cta, in print. Byrne C. R., M onroe R. S., Ward K. H. and Kredich N. M. (1988), D N A sequence of the cysK regions of Salmonella typhimurium and Escherichia coli and linkage to the cysK regions o f pfsH . J. Bacteriol. 170, 3150-3157. Clarkson D. T., Hawkesford M. C. and Davidian J.-C. (1993), Membrane and long-distance transport sul fate, in: Sulfur Nutrition and Assimilation in Higher Plants (L. J. de Kok et al., eds.). SBP Academ ic Publ., The Hague, pp. 3 -1 9 . Cram W. J. (1990), Uptake and transport of sulfate, in: Sulfur Nutrition and Sulfur Assimilation in Higher Plants (H. Rennenberg et al., eds.). SPB Academic Publ., The Hague, pp. 3 -1 1 . Flügge U. T" Fischer K., Gross A., Sebald A., Lottspeich K. and Eckerskorn C. (1989), The triose phosphate -3-phosphoglycerate -phosphate translocator from spinach chloroplasts: Nucleotide sequence of a fulllength cD N A clone and import of the in vitro synthe sized precursor protein into chloroplasts. EM BO J. 8 , 3 9 -4 6 .
doi:10.1515/znc-1994-9-1001 fatcat:2mihvhpevrarfecjdxllq3lbfy