Nucleotide utilization requirements that render ClpB active as a chaperone

• Published in: FEBS letters 2010-03, Vol.584 (5), p.929-934
• Main Authors: Castillo, Urko del, Fernández-Higuero, José Ángel, Pérez-Acebrón, Sergio, Moro, Fernando, Muga, Arturo
• Format: Article
• Language: English
• Subjects: Adenosine Triphosphate - metabolism; Aggregate reactivation; Bacterial Proteins - chemistry; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Chaperones; Chromatography, Gel; ClpB; ClpB from Thermus thermophilus; ClpB(E279A); ClpB(E279A/E678A); ClpB(E279A/K611A); ClpB(E678A); ClpB(K212A/E678A); ClpB(K611A); Endopeptidase Clp; Escherichia coli Proteins - chemistry; Escherichia coli Proteins - genetics; Escherichia coli Proteins - metabolism; Heat-Shock Proteins - chemistry; Heat-Shock Proteins - genetics; Heat-Shock Proteins - metabolism; Molecular Chaperones - chemistry; Molecular Chaperones - genetics; Molecular Chaperones - metabolism; N1T2; Nucleotides - metabolism; Protein Binding; Protein Multimerization; Protein oligomer; T1N2; T1T2; TClpB
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/j.febslet.2010.01.029

ClpB is a member of the AAA+ superfamily that forms a ring-shaped homohexamer. Each protomer contains two nucleotide binding domains arranged in two rings that hydrolyze ATP. We extend here previous studies on ClpB nucleotide utilization requirements by using an experimental approach that maximizes random incorporation of different subunits into the protein hexamer. Incorporation of one subunit unable to bind or hydrolyze ATP knocks down the chaperone activity, while the wt hexamer can accommodate two mutant subunits that hydrolyze ATP in only one protein ring. Four subunits seem to build the functional cooperative unit, provided that one of the protein rings contains active nucleotide binding sites.