The chromosomal protein sso7d of the crenarchaeon Sulfolobus solfataricus rescues aggregated proteins in an ATP hydrolysis-dependent manner.
In this work, we show that the nonspecific DNA-binding protein Sso7d from the crenarchaeon Sulfolobus solfataricus displays a cation-dependent ATPase activity with a pH optimum around neutrality and a temperature optimum of 70 degrees C. Measurements of tryptophan fluorescence and experiments that used 1-anilinonaphthalene-8-sulfonic acid as probe demonstrated that ATP hydrolysis induces a conformational change in the molecule and that the binding of the nucleotide triggers the ATP hydrolysis-induced conformation of the protein to return to the native conformation. We found that Sso7d rescues previously aggregated proteins in an ATP hydrolysis-dependent manner; the native conformation of Sso7d forms a complex with the aggregates, while the ATP hydrolysis-induced conformation is incapable of this interaction. Sso7d is believed to be the first protein isolated from an archaeon capable of rescuing aggregates.
Guagliardi
A
A
Dipartimento di Chimica Organica e Biologica, Università di Napoli, Via Mezzocannone 16, 80134 Napoli, and the Istituto di Biochimica delle Proteine ed Enzimologia, Consiglio Nazionale delle Ricerche, Via Marconi 10, 80125 Napoli, Italy. guaglia@unina.it
Cerchia
L
L
Moracci
M
M
Rossi
M
M
D000251:Adenosine Triphosphatases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism; D019843:Archaeal Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D002868:Chromosomal Proteins, Non-Histone / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D005453:Fluorescence; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008247:Lysosomes / Q000737:chemistry / Q000378:metabolism; D008291:Malate Dehydrogenase / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation; D011489:Protein Denaturation; D017510:Protein Folding; D012995:Solubility; D016944:Sulfolobus / Q000201:enzymology*; D013696:Temperature; D014364:Tryptophan / Q000737:chemistry / Q000378:metabolism
D019843:Archaeal Proteins; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; C093228:Sso7d protein, Sulfolobus; D014364:Tryptophan; D000255:Adenosine Triphosphate; D008291:Malate Dehydrogenase; C034544:D-malate dehydrogenase (decarboxylating); D000251:Adenosine Triphosphatases