An archaeal orthologue of the universal protein Kae1 is an iron metalloprotein which exhibits atypical DNA-binding properties and apurinic-endonuclease activity in vitro.
The Kae1 (Kinase-associated endopeptidase 1) protein is a member of the recently identified transcription complex EKC and telomeres maintenance complex KEOPS in yeast. Kae1 homologues are encoded by all sequenced genomes in the three domains of life. Although annotated as putative endopeptidases, the actual functions of these universal proteins are unknown. Here we show that the purified Kae1 protein (Pa-Kae1) from Pyrococcus abyssi is an iron-protein with a novel type of ATP-binding site. Surprisingly, this protein did not exhibit endopeptidase activity in vitro but binds cooperatively to single and double-stranded DNA and induces unusual DNA conformational change. Furthermore, Pa-Kae1 exhibits a class I apurinic (AP)-endonuclease activity (AP-lyase). Both DNA binding and AP-endonuclease activity are inhibited by ATP. Kae1 is thus a novel and atypical universal DNA interacting protein whose importance could rival those of RecA (RadA/Rad51) in the maintenance of genome integrity in all living cells.
Hecker
Arnaud
A
Institut de Génétique et Microbiologie, Univ. Paris-Sud, IFR115, UMR8621-CNRS, 91405 Orsay, France.
Leulliot
Nicolas
N
Gadelle
Danièle
D
Graille
Marc
M
Justome
Anthony
A
Dorlet
Pierre
P
Brochier
Céline
C
Quevillon-Cheruel
Sophie
S
Le Cam
Eric
E
van Tilbeurgh
Herman
H
Forterre
Patrick
P
D000255:Adenosine Triphosphate / Q000378:metabolism; D019843:Archaeal Proteins / Q000737:chemistry* / Q000145:classification / Q000378:metabolism; D004247:DNA / Q000648:ultrastructure; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase / Q000737:chemistry* / Q000145:classification / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000145:classification / Q000378:metabolism; D033862:Iron-Binding Proteins / Q000737:chemistry* / Q000145:classification / Q000378:metabolism; D008666:Metalloendopeptidases / Q000145:classification; D008958:Models, Molecular; D010802:Phylogeny; D043903:Pyrococcus abyssi / Q000201:enzymology*
D019843:Archaeal Proteins; D004268:DNA-Binding Proteins; D033862:Iron-Binding Proteins; D000255:Adenosine Triphosphate; D004247:DNA; D008666:Metalloendopeptidases; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase