Identification of a Functional Type IA Topoisomerase, LdTopIII?, from Kinetoplastid Parasite Leishmania donovani.

ABSTRACT: DNA topoisomerases of kinetoplastids represent a family of DNA processing enzymes that essentially solve the topological problems not only in nuclear DNA but also in kinetoplast DNA. We have, for the first time, identified a Leishmania donovani homologue of bacterial and eukaryotic IA type of topoisomerase III protein and termed as LdTopIII?. Complementation study of wild-type and mutant LdTopIII? with slow-growing topoisomerase III mutant yeast S. cerevisiae revealed the functional conservation of the leishmanial counterpart of topoisomerase III? protein, the 327 tyrosine being the active site amino acid. A C-terminal deletion construct of LdTopIII? could not suppress the slow-growth phenotype of mutant yeast, indicating the requirement of C-terminal region for the enzyme function in vivo.LdTopIII? localized inside the nucleus and kinetoplast of the parasite. Taken together, our study indicates functional conservation and possible role of LdTopIII? in parasite DNA processing.

SUBMITTER: Banerjee B 

PROVIDER: S-EPMC3102327 | biostudies-literature | 2011

REPOSITORIES: biostudies-literature