title: Catalytic and regulatory properties of sulphur metabolizing enzymes in cyanobacterium Synechococcus elongatus PCC 7942.
abstract: Synechococcus elongatus PCC 7942 was able to grow with several S sources. The sulphur metabolizing enzymes viz. ATP sulphurylase, cysteine synthase, thiosulphate reductase and L- and D-cysteine desulphydrases were regulated by sulphur sources, particularly by sulphur amino acids and organic sulphate esters. Sulphur starvation reduced ATP sulphurylase and cysteine synthase whereas reduced glutathione appreciated Cys degradation activity. With partially purified enzymes apparent Km values for sulphate, ATP, D- and L-Cys, thiosulphate, sulphide and O-acetyl serine were in a range of 12-50 microM. p-Nitrophenyl sulphate inhibited ATP sulphurylase competitively. Met was a feedback inhibitor of several key enzymes.
authors.affiliation: Department of Biological Sciences, Rani Durgavati University, Jabalpur, India.
authors.forename: Anuradha
authors.initials: A
authors.lastname: Jain
authors.forename: Deepti
authors.initials: D
authors.lastname: Verma
authors.forename: Divya
authors.initials: D
authors.lastname: Bagchi
mesh_terms: D002384:Catalysis; D002848:Chromatography, DEAE-Cellulose; D003542:Cystathionine gamma-Lyase / Q000037:antagonists & inhibitors / Q000378:metabolism; D003547:Cysteine Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D050862:Oxidoreductases Acting on Sulfur Group Donors / Q000037:antagonists & inhibitors / Q000378:metabolism; D013430:Sulfate Adenylyltransferase / Q000037:antagonists & inhibitors / Q000378:metabolism; D013457:Sulfur Compounds / Q000378:metabolism*; D013466:Sulfurtransferases; D046940:Synechococcus / Q000187:drug effects / Q000201:enzymology* / Q000254:growth & development
chemical_list: D004791:Enzyme Inhibitors; D013457:Sulfur Compounds; D050862:Oxidoreductases Acting on Sulfur Group Donors; D003547:Cysteine Synthase; D013430:Sulfate Adenylyltransferase; D013466:Sulfurtransferases; C022747:thiosulfate-dithiol sulfurtransferase; D003542:Cystathionine gamma-Lyase