Characterization of a novel Obg-like ATPase in the protozoan Trypanosoma cruzi.
We characterized a gene encoding an YchF-related protein, TcYchF, potentially associated with the protein translation machinery of Trypanosoma cruzi. YchF belongs to the translation factor-related (TRAFAC) class of P-loop NTPases. The coding region of the gene is 1185bp long and encodes a 44.3kDa protein. BlastX searches showed TcYchF to be very similar (45-86%) to putative GTP-binding proteins from eukaryotes, including some species of trypanosomatids (Leishmania major and Trypanosoma brucei). A lower but significant level of similarity (38-43%) was also found between the predicted sequences of TcYchF and bacterial YyaF/YchF GTPases of the Spo0B-associated GTP-binding protein (Obg) family. Some of the most important features of the G domain of this family of GTPases are conserved in TcYchF. However, we found that TcYchF preferentially hydrolyzed ATP rather than GTP. The function of YyaF/YchF is unknown, but other members of the Obg family are known to be associated with ribosomal subunits. Immunoblots of the polysome fraction from sucrose gradients showed that TcYchF was associated with ribosomal subunits and polysomes. Immunoprecipitation assays showed that TcYchF was also associated with the proteasome of T. cruzi. Furthermore, inactivation of the T. brucei homolog of TcYchF by RNA interference inhibited the growth of procyclic forms of the parasite. These data suggest that this protein plays an important role in the translation machinery of trypanosomes.
Gradia
Daniela F
DF
Instituto de Biologia Molecular do Paraná, Rua Professor Algacyr Munhoz Mader 3775, Curitiba 81350-010, Paraná, Brasil.
Rau
Karlan
K
Umaki
Adriana C S
AC
de Souza
Flavia S P
FS
Probst
Christian M
CM
Correa
Alejandro
A
Holetz
Fabíola B
FB
Avila
Andréa R
AR
Krieger
Marco A
MA
Goldenberg
Samuel
S
Fragoso
Stenio P
SP
D000251:Adenosine Triphosphatases / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D001483:Base Sequence; D020558:GTP Phosphohydrolases / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000235:genetics; D017125:Genes, Protozoan; D008297:Male; D008969:Molecular Sequence Data; D016053:RNA, Protozoan / Q000378:metabolism; D011817:Rabbits; D014346:Trypanosoma brucei brucei / Q000235:genetics*; D014349:Trypanosoma cruzi / Q000235:genetics*
D016053:RNA, Protozoan; D000251:Adenosine Triphosphatases; D020558:GTP Phosphohydrolases; D019204:GTP-Binding Proteins