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Updated: Jul 15, 2025
Deciphering the Molecular Mechanism and Function of Pore-Forming Toxins Using Leishmania major
Published on: October 28, 2022
Biochemical and structural characterization of the RT domain of Leishmania sp. telomerase reverse transcriptase
Vitor Luiz da Silva1, Stephany Cacete de Paiva1, Hamine Cristina de Oliveira2
1Department of Chemical and Biological Sciences, Institute of Biosciences, São Paulo State University (UNESP), Botucatu, SP, Brazil.
Background:
The Leishmania genus comprises parasites that cause leishmaniasis, a neglected disease spread worldwide. Leishmania sp. telomeres are composed of TTAGGG repeats maintained by telomerase. In most eukaryotes, the enzyme minimal complex contains the TER (telomerase RNA) and the TERT (telomerase reverse transcriptase) components. The TERT holds the enzyme catalytic core and is formed by four structural and functional domains (TEN, Telomerase Essential N-terminal; TRBD, Telomerase RNA Binding Domain; RT, the reverse transcriptase domain and CTE, C-Terminal Extension domain).
Methods And Results:
Amino acid sequence alignments, protein structure prediction analysis, and protein: nucleic acid interaction assays were used to show that the Leishmania major RT domain preserves the canonical structural elements found in higher eukaryotes, including the canonical motifs and the aspartic acid residues that stabilize the Mg2+ ion cofactor. Furthermore, amino acid substitutions specific to the Leishmania genus and partial conservation of the residues involved with nucleic acid interactions are shown. The purified recombinant Leishmania RT protein is biochemically active and interacts with the G-rich telomeric strand and the TER template sequence.
Conclusion:
Our results highlight that the telomerase catalysis mechanism is conserved in a pathogen of medical importance despite the structural peculiarities present in the parasite's RT domain.
