Interaction of sulfite with the noncatalytic and catalytic sites of chloroplast coupling factor cf1.
The interaction between sulfite, an efficient Mg2+-dependent F1-ATPase activator, and chloroplast CF1-ATPase was studied. The sulfite anion was shown to inhibit ADP and ATP binding to the noncatalytic sites of CF1. The stimulating activity of sulfite persists when all noncatalytic sites are nucleotide-occupied. Phosphate, a competing candidate for binding to CF1 catalytic sites, suppresses this activity. These results support the suggestion that the stimulation of Mg2+-dependent ATPase activity of CF1 is caused by sulfite binding to its catalytic sites.
Malyan
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Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia. Malyan@issp.serpukhov.su
Vitseva
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D000227:Adenine Nucleotides / Q000737:chemistry / Q000378:metabolism; D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000737:chemistry / Q000378:metabolism; D017301:Ca(2+) Mg(2+)-ATPase / Q000378:metabolism; D020134:Catalytic Domain / Q000502:physiology; D006868:Hydrolysis; D011485:Protein Binding / Q000187:drug effects / Q000502:physiology; D006180:Proton-Translocating ATPases / Q000737:chemistry / Q000378:metabolism*; D018724:Spinacia oleracea / Q000201:enzymology; D013447:Sulfites / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology
D000227:Adenine Nucleotides; D013447:Sulfites; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; D017301:Ca(2+) Mg(2+)-ATPase; D006180:Proton-Translocating ATPases