1yvb
the Plasmodium falciparum Cysteine Protease Falcipain-2the Plasmodium falciparum Cysteine Protease Falcipain-2
Structural highlights
FunctionFPC2A_PLAF7 Cysteine protease which cleaves native host hemoglobin and globin in the food vacuole during the asexual blood stage (PubMed:10887194, PubMed:15070727, PubMed:15964982, PubMed:16777845, PubMed:19357776, PubMed:25791019). The binding to host hemoglobin is pH-sensitive and only occurs at acidic pH (PubMed:16777845). Cleaves ankyrin and protein 4.1, two components of host erythrocyte membrane cytoskeleton required for the stability of the erythrocyte membrane, and thus may be involved in parasite release (PubMed:11463472). Preferentially cleaves substrates which have an arginine or lysine at the P1 position and a leucine or phenylalanine at the P2 position (PubMed:10887194, PubMed:19357776).[1] [2] [3] [4] [5] [6] [7] Evolutionary Conservation![]() Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedFalcipain-2 (FP2), the major cysteine protease of the human malaria parasite Plasmodium falciparum, is a hemoglobinase and promising drug target. Here we report the crystal structure of FP2 in complex with a protease inhibitor, cystatin. The FP2 structure reveals two previously undescribed cysteine protease structural motifs, designated FP2(nose) and FP2(arm), in addition to details of the active site that will help focus inhibitor design. Unlike most cysteine proteases, FP2 does not require a prodomain but only the short FP2(nose) motif to correctly fold and gain catalytic activity. Our structure and mutagenesis data suggest a molecular basis for this unique mechanism by highlighting the functional role of two Tyr within FP2(nose) and a conserved Glu outside this motif. The FP2(arm) motif is required for hemoglobinase activity. The structure reveals topographic features and a negative charge cluster surrounding FP2(arm) that suggest it may serve as an exo-site for hemoglobin binding. Motifs similar to FP2(nose) and FP2(arm) are found only in related plasmodial proteases, suggesting that they confer malaria-specific functions. Structural basis for unique mechanisms of folding and hemoglobin binding by a malarial protease.,Wang SX, Pandey KC, Somoza JR, Sijwali PS, Kortemme T, Brinen LS, Fletterick RJ, Rosenthal PJ, McKerrow JH Proc Natl Acad Sci U S A. 2006 Aug 1;103(31):11503-8. Epub 2006 Jul 24. PMID:16864794[8] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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