ATPase site architecture is required for self-assembly and remodeling activity of a hexameric AAA+ transcriptional activator.
AAA+ proteins (ATPases associated with various cellular activities) are oligomeric ATPases that use ATP hydrolysis to remodel their substrates. By similarity with GTPases, a dynamic organization of the nucleotide-binding pockets between ATPase protomers is proposed to regulate functionality. Using the transcription activator PspF as an AAA+ model, we investigated contributions of conserved residues for roles in ATP hydrolysis and intersubunit communication. We determined the R-finger residue and revealed that it resides in a conserved "R-hand" motif (R(x)D(xxx)R) needed for its "trans-acting" activity. Further, a divergent Walker A glutamic acid residue acts synergistically with a tyrosine residue to function in ADP-dependent subunit-subunit coordination, forming the "ADP-switch" motif. Another glutamic acid controls hexamer formation in the presence of nucleotides. Together, these results lead to a "residue-nucleotide" interaction map upon which to base AAA+ core regulation.
Division of Biology, Sir Alexander Fleming Building, Imperial College London, London SW7 2AZ, UK. joly@ijm.univ-paris-diderot.fr
Nicolas
N
Joly
Nan
N
Zhang
Martin
M
Buck
D000251:Adenosine Triphosphatases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D020816:Amino Acid Motifs / Q000235:genetics; D000595:Amino Acid Sequence; D017124:Conserved Sequence; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary / Q000235:genetics; D015534:Trans-Activators / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D015533:Transcriptional Activation / Q000235:genetics*
D029968:Escherichia coli Proteins; C098954:PspF protein, E coli; D015534:Trans-Activators; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases