Abstract of the PDB Structure's related Publication:
Kae1 is a universally conserved ATPase and part of the essential gene set in bacteria. In archaea and eukaryotes, Kae1 is embedded within the protein kinase-containing KEOPS complex. Mutation of KEOPS subunits in yeast leads to striking telomere and transcription defects, but the exact biochemical function of KEOPS is not known. As a first step to elucidating its function, we solved the atomic structure of archaea-derived KEOPS complexes involving Kae1, Bud32, Pcc1, and Cgi121 subunits. Our studies suggest that Kae1 is regulated at two levels by the primordial protein kinase Bud32, which is itself regulated by Cgi121. Moreover, Pcc1 appears to function as a dimerization module, perhaps suggesting that KEOPS may be a processive molecular machine. Lastly, as Bud32 lacks the conventional substrate-recognition infrastructure of eukaryotic protein kinases including an activation segment, Bud32 may provide a glimpse of the evolutionary history of the protein kinase family.
Absent in bacteria, present only in eykaryota and archaea. Works with other proteins of the KEC/KEOPS complex Bud32, Pcc1 and possibly Gon7. It is probably involved in the transfer of the threonylcarbamoyl moiety of threonylcarbamoyl-AMP (TC-AMP) to the N6 group of A37, a step in the formation of a threonylcarbamoyl group on adenosine at position 37 (t(6)A37) in tRNAs that read codons beginning with adenine. Cgi121 stimulates Bud32 kinase activity via an activation of Bud32 autophosphorylation.
Atomic structure of the KEOPS complex: an ancient protein kinase-containing molecular machine.
Mao DY, Neculai D, Downey M, Orlicky S, Haffani YZ, Ceccarelli DF, Ho JS, Szilard RK, Zhang W, Ho CS, Wan L, Fares C, Rumpel S, Kurinov I, Arrowsmith CH, Durocher D, Sicheri F