A histidine in the beta-CASP domain of Artemis is critical for its full in vitro and in vivo functions.
Artemis is a key factor of the nonhomologous end-joining (NHEJ) pathway, which is critical for DNA double-strand break (DSB) repair in eukaryotic cells. It belongs to the beta-CASP family of nucleases, forming a distinct group within the metallo-beta-lactamase superfamily. Proteins of this group are specific for nucleic acids and contain an original domain, the beta-CASP domain, which serves as a cap covering the active site displayed by the metallo-beta-lactamase domain.Here, we have identified in the highly divergent sequences of the beta-CASP domains from DNA-specific nucleases two conserved residues (Artemis E213 and H254), which are not present in RNA-specific enzymes, and shown that H254 plays a key role in the Artemis function, as it is critical for its full activity in vitro. Moreover, inherited mutation of H254 results in radiosensitive severe combined immune deficiency (RS-SCID) in humans. This residue might play a key role in specificity towards DNA, if not directly in zinc binding.
de Villartay
Jean-Pierre
JP
INSERM U768, Unité Développement Normal et Pathologique du Système Immunitaire, Hôpital Necker-Enfants Malades,149 rue de Sèvres, Paris F-75015, France. jean-pierre.de-villartay@inserm.fr
Shimazaki
Noriko
N
Charbonnier
Jean-Baptiste
JB
Fischer
Alain
A
Mornon
Jean-Paul
JP
Lieber
Michael R
MR
Callebaut
Isabelle
I
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001483:Base Sequence; D017124:Conserved Sequence; D004247:DNA / Q000378:metabolism; D004252:DNA Mutational Analysis; D004268:DNA-Binding Proteins; D004720:Endonucleases; D006367:HeLa Cells; D006639:Histidine / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D050505:Mutant Proteins / Q000378:metabolism; D009687:Nuclear Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D016511:Severe Combined Immunodeficiency / Q000201:enzymology; D013329:Structure-Activity Relationship
D004268:DNA-Binding Proteins; D050505:Mutant Proteins; D009687:Nuclear Proteins; D006639:Histidine; D004247:DNA; C426344:DCLRE1C protein, human; D004720:Endonucleases