A novel DNA repair enzyme containing RNA recognition, G-patch and specific splicing factor 45-like motifs in the protozoan parasite Toxoplasma gondii.
We report the cloning and functional characterization of the full-length cDNA and gene encoding a Toxoplasma gondii DNA repair enzyme designated TgDRE. The gene is composed of three exons separated by two introns of 780 and 630 bp, and encodes a protein with a predicted molecular mass of 49.6 kDa. The native TgDRE protein, with a molecular mass of 60 kDa, is only detected in the virulent tachyzoite stage of T. gondii. However, the transcript is present in both asexual parasite stages, virulent tachyzoite and avirulent encysted bradyzoite. When an Escherichia coli mutant lacking ruvC endonuclease and recG helicase was transformed with TgDRE cDNA, a significant increase in resistance to DNA-damaging agents, such as UV light and mitomycin C, was observed. Moreover, database searches revealed that TgDRE orthologues were present in the genome sequences of the related apicomplexa parasites Plasmodium falciparum and Plasmodium yoelii, as well as in those of Arabidopsis thaliana, Drosophila melanogaster, Caenorhabditis elegans and Homo sapiens. This novel family of proteins is characterized by the presence of human splicing factor SF45-like, RNA recognition (RRM) and glycine-rich (G-patch) motifs. The presence of these motifs suggests that T. gondii TgDRE might also be involved in other biological functions such as RNA metabolism in addition to DNA-repair.
Equipe de Parasitologie Moléculaire, Laboratoire de Chimie Biologique, CNRS UMR 8576, Université des Sciences et Technologies de Lille, France.
Najoua
N
Dendouga
Isabelle
I
Callebaut
Stanislas
S
Tomavo
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D029681:Arabidopsis Proteins / Q000737:chemistry; D003001:Cloning, Molecular; D004249:DNA Damage; D011088:DNA Ligases / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D004260:DNA Repair; D004269:DNA, Bacterial / Q000378:metabolism / Q000528:radiation effects; D018076:DNA, Complementary / Q000235:genetics; D016054:DNA, Protozoan / Q000235:genetics; D004706:Endodeoxyribonucleases / Q000172:deficiency / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects; D029968:Escherichia coli Proteins / Q000235:genetics; D019143:Evolution, Molecular; D017125:Genes, Protozoan; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D012313:RNA / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D016415:Sequence Alignment; D017385:Sequence Homology; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D014122:Toxoplasma / Q000201:enzymology* / Q000235:genetics; D014466:Ultraviolet Rays
D029681:Arabidopsis Proteins; D004269:DNA, Bacterial; D018076:DNA, Complementary; D016054:DNA, Protozoan; D029968:Escherichia coli Proteins; D015800:Protozoan Proteins; D011993:Recombinant Fusion Proteins; C069806:ruvC protein, E coli; C071446:RecG protein, E coli; D012313:RNA; D004706:Endodeoxyribonucleases; D011088:DNA Ligases; C465218:DNA repair enzyme TgDRE, Toxoplasma gondii; C465219:DRT111 protein, Arabidopsis