title: Biochemical characterization of sulfur assimilation by Salmonella pullorum.
abstract: The biochemical basis for a cysteine requirement in Salmonella pullorum strain MS35 is presented. Before determining the missing biochemical functions, it was established that the assimilatory sulfate-reducing pathway for this species is an inorganic one in which 3'-phosphoadenylylsulfate (PAPS), sulfite, and sulfide are intermediates. A requirement for 2'- and 3'-adenosine monophosphate was found for in vitro synthesis of PAPS, possibly because 2'- and 3'-adenosine monophosphate inhibits endogenous nucleases that destroy PAPS. The cysteine requirement of strain MS35 was attributed to a defect at 37 C in sulfate permeation and temperature sensitivity in sulfite reduction. At 25 C, sulfite was metabolized to sulfide. A novel property of sulfate-utilizing revertants was their unselected ability to assimilate thiosulfate sulfur at 25 C but not at 37 C.
mesh_terms: D001692:Biological Transport; D002845:Chromatography; D003470:Culture Media; D003545:Cysteine; D004586:Electrophoresis; D009711:Nucleotides / Q000096:biosynthesis; D010088:Oxidoreductases / Q000378:metabolism; D012475:Salmonella / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*; D012486:Salmonella typhimurium / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism; D013053:Spectrophotometry; D013431:Sulfates / Q000378:metabolism; D013440:Sulfides / Q000378:metabolism; D013447:Sulfites / Q000378:metabolism; D013455:Sulfur / Q000378:metabolism*; D013460:Sulfur Isotopes; D013696:Temperature
chemical_list: D003470:Culture Media; D009711:Nucleotides; D013431:Sulfates; D013440:Sulfides; D013447:Sulfites; D013460:Sulfur Isotopes; D013455:Sulfur; D010088:Oxidoreductases; D003545:Cysteine