The D arm of tRNATyr is Necessary and Sufficient for Import into Leishmania Mitochondria in Vitro
IR@IICB: CSIR-Indian Institute of Chemical Biology, Kolkata
View Archive Info| Field | Value | |
| Title |
The D arm of tRNATyr is Necessary and Sufficient for
Import into Leishmania Mitochondria in Vitro
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| Creator |
Mahapatra, Sridam
Ghosh, Subhagata Bera, Saphal Kanti Ghosh, Trina Das, Anish Adhya, Samit |
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| Subject |
Molecular & Human Genetics
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| Description |
Transfer RNAs are selectively imported from the
cytoplasm into mitochondria of kinetoplastid protozoa
such as Leishmania. The specific structural features of
tRNA which determine selectivity are largely unknown.
Using an in organello system from Leishmania, the
import signals on tRNATyr and on a synthetic transcript
which binds to the same receptor, were studied by
deletion and reconstruction analyses. In both cases,
short oligoribonucleotides (minihelices) containing
the sequence UGGYAGAG were imported with high
efficiency in the presence of ATP. This motif is present
in the D arm of tRNATyr, as well as in the majority of
imported Leishmania tRNAs. Deletion of the D arm, or
a point mutation in the conserved motif, reduces
importability. The import signal coincides with the
binding site for the mitochondrial receptor TAB.
tRNAGln, which is not imported, forms non-productive,
TAB-independent complexes with the mitochondrial
surface. However, the observation that the
imported:bound ratio of the D arm minihelix is higher
than that of the entire molecule suggests that the
post-binding translocation step is constrained in
terms of size or structural flexibility. Kinetic studies of
minihelix import indicate stepwise insertion of the
molecule into import channels.
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| Date |
1998
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| Type |
Article
PeerReviewed |
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| Format |
application/pdf
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| Identifier |
http://www.eprints.iicb.res.in/826/1/NUCLEIC_ACIDS_RESEARCH%2C_26(_9)%2C_2037%2D2041[44].pdf
Mahapatra, Sridam and Ghosh, Subhagata and Bera, Saphal Kanti and Ghosh, Trina and Das, Anish and Adhya, Samit (1998) The D arm of tRNATyr is Necessary and Sufficient for Import into Leishmania Mitochondria in Vitro. Nucleic Acids Research, 26 (9). pp. 2037-2041. |
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| Relation |
http://dx.doi.org/10.1093/nar/26.9.2037
http://www.eprints.iicb.res.in/826/ |
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