3NV9

Crystal structure of Entamoeba histolytica Malic Enzyme

Summary for 3NV9

• Entry DOI: 10.2210/pdb3nv9/pdb
• Descriptor: Malic enzyme, SULFATE ION, SODIUM ION, ... (6 entities in total)
• Functional Keywords: rossmann fold, oxidoreductase
• Biological source: Entamoeba histolytica
• Total number of polymer chains: 2
• Total formula weight: 109166.64

Authors

Dutta, D.,Chakrabarty, A.,Ghosh, S.K.,Das, A.K. (deposition date: 2010-07-08, release date: 2011-07-20, Last modification date: 2025-06-25)

Primary citation

Chakrabarty, A.,Dutta, D.,Baidya, M.,Dutta, A.,Das, A.K.,Ghosh, S.K.
Metronidazole Activation by a Deeply Entangled Dimeric Malic Enzyme in Entamoeba histolytica.
Pathogens, 14:-, 2025

PubMed Abstract: Metronidazole is the preferred drug for treating amoebiasis caused by . Its antiamoebic activity is primarily attributed to activation by various reductases. This study reports an alternative activation pathway in mediated by the decarboxylating malic enzyme. Functional characterization of this NADPH-dependent enzyme reveals that it is secreted into the extracellular milieu and may play a role in adhesion to human enteric cells. Structural analysis of the malic enzyme (EhME) demonstrates that the protein forms a strict dimer, with the protomers interlocked by a unique knot structure formed by two polypeptide chains. This distinctive structural feature closely aligns EhME with its prokaryotic counterparts. In conclusion, our findings reveal that harbors a deeply entangled dimeric malic enzyme that contributes to metronidazole susceptibility, sharing structural similarities with bacterial malic enzymes.

PubMed: 40137762
DOI: 10.3390/pathogens14030277

Experimental method

X-RAY DIFFRACTION (2.25 Å)