Molecular cloning and expression of adenosine kinase from Leishmania donovani : identification of unconventional P-loop motif
IR@IICB: CSIR-Indian Institute of Chemical Biology, Kolkata
View Archive Info| Field | Value | |
| Title |
Molecular cloning and expression of adenosine kinase from Leishmania
donovani : identification of unconventional P-loop motif
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| Creator |
Sinha, Krishna Murari
Ghosh, Mallika Das, Ishita Datta, Alok K |
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| Subject |
Structural Biology & Bioinformatics
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| Description |
The unique catalytic characteristics of adenosine kinase (Adk)
and its stage-speci®c differential activity pattern have made this
enzyme a prospective target for chemotherapeutic manipulation
in the purine-auxotrophic parasitic protozoan Leishmania
dono�ani. However, nothing is known about the structure of the
parasite Adk. We report here the cloning of its gene and the
characterization of the gene product. The encoded protein,
consisting of 345 amino acid residues with a calculated molecular
mass of 37173 Da, shares limited but signi®cant similarity with
sugar kinases and inosine±guanosine kinase of microbial origin,
supporting the notion that these enzymes might have the same
ancestral origin. The identity of the parasite enzyme with the
corresponding enzyme from two other sources so far described
was only 40%. Furthermore, 5« RNA mapping studies indicated
that the Adk gene transcript is matured post-transcriptionally with the trans-splicing of the mini-exon (spliced leader) occurring
at nt ®160 from the predicted translation initiation site. The
biochemical properties of the recombinant enzyme were similar
to those of the enzyme isolated from leishmanial cells. The
intrinsic tryptophan ¯uorescence of the enzyme was substratesensitive.
On the basis of a multiple protein-alignment sequence
comparison and ATP-induced ¯uorescence quenching in the
presence or the absence of KI and acrylamide, the docking site
for ATP has been provisionally identi®ed and shown to have
marked divergence from the consensus P-loop motif reported for
ATP- or GTP-binding proteins from other sources.
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| Publisher |
Portland Press
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| Date |
1999
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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/656/1/BIOCHEMICAL_JOURNAL_339%2C_667%2D673;1999[56].pdf
Sinha, Krishna Murari and Ghosh, Mallika and Das, Ishita and Datta, Alok K (1999) Molecular cloning and expression of adenosine kinase from Leishmania donovani : identification of unconventional P-loop motif. Biochemical Journal, 339. pp. 667-673. ISSN 0264-6021 |
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| Relation |
http://dx.doi.org/10.1042/0264-6021:3390667
http://www.eprints.iicb.res.in/656/ |
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