Structure-function analysis of nucleotide housekeeping protein HAM1 from human malaria parasite Plasmodium falciparum.

Autor: Saha D; Division of Infectious Diseases and Immunology, CSIR-Indian Institute of Chemical Biology, Kolkata, India., Pramanik A; Division of Structural Biology & Bioinformatics, CSIR-Indian Institute of Chemical Biology, Kolkata, India., Freville A; Department of Infection Biology, London School of Hygiene & Tropical Medicine, UK., Siddiqui AA; Division of Infectious Diseases and Immunology, CSIR-Indian Institute of Chemical Biology, Kolkata, India., Pal U; Division of Structural Biology & Bioinformatics, CSIR-Indian Institute of Chemical Biology, Kolkata, India., Banerjee C; Division of Infectious Diseases and Immunology, CSIR-Indian Institute of Chemical Biology, Kolkata, India., Nag S; Division of Infectious Diseases and Immunology, CSIR-Indian Institute of Chemical Biology, Kolkata, India., Debsharma S; Division of Infectious Diseases and Immunology, CSIR-Indian Institute of Chemical Biology, Kolkata, India., Pramanik S; Division of Infectious Diseases and Immunology, CSIR-Indian Institute of Chemical Biology, Kolkata, India., Mazumder S; Department of Zoology, Raja Peary Mohan College, Uttarpara, India., Maiti NC; Division of Structural Biology & Bioinformatics, CSIR-Indian Institute of Chemical Biology, Kolkata, India., Datta S; Division of Structural Biology & Bioinformatics, CSIR-Indian Institute of Chemical Biology, Kolkata, India., van Ooij C; Department of Infection Biology, London School of Hygiene & Tropical Medicine, UK., Bandyopadhyay U; Division of Infectious Diseases and Immunology, CSIR-Indian Institute of Chemical Biology, Kolkata, India.; Department of Biological Sciences, Bose Institute, Kolkata, India.
Jazyk: angličtina
Zdroj: The FEBS journal [FEBS J] 2024 Oct; Vol. 291 (19), pp. 4349-4371. Date of Electronic Publication: 2024 Jul 14.
DOI: 10.1111/febs.17216
Abstrakt: Non-canonical nucleotides, generated as oxidative metabolic by-products, significantly threaten the genome integrity of Plasmodium falciparum and thereby, their survival, owing to their mutagenic effects. PfHAM1, an evolutionarily conserved inosine/xanthosine triphosphate pyrophosphohydrolase, maintains nucleotide homeostasis in the malaria parasite by removing non-canonical nucleotides, although structure-function intricacies are hitherto poorly reported. Here, we report the X-ray crystal structure of PfHAM1, which revealed a homodimeric structure, additionally validated by size-exclusion chromatography-multi-angle light scattering analysis. The two monomeric units in the dimer were aligned in a parallel fashion, and critical residues associated with substrate and metal binding were identified, wherein a notable structural difference was observed in the β-sheet main frame compared to human inosine triphosphate pyrophosphatase. PfHAM1 exhibited Mg ++ -dependent pyrophosphohydrolase activity and the highest binding affinity to dITP compared to other non-canonical nucleotides as measured by isothermal titration calorimetry. Modifying the pfham1 genomic locus followed by live-cell imaging of expressed mNeonGreen-tagged PfHAM1 demonstrated its ubiquitous presence in the cytoplasm across erythrocytic stages with greater expression in trophozoites and schizonts. Interestingly, CRISPR-Cas9/DiCre recombinase-guided pfham1-null P. falciparum survived in culture under standard growth conditions, indicating its assistive role in non-canonical nucleotide clearance during intra-erythrocytic stages. This is the first comprehensive structural and functional report of PfHAM1, an atypical nucleotide-cleansing enzyme in P. falciparum.
(© 2024 Federation of European Biochemical Societies.)
Databáze: MEDLINE
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