2ghu
From Proteopedia
(New page: 200px<br /><applet load="2ghu" size="350" color="white" frame="true" align="right" spinBox="true" caption="2ghu, resolution 3.1Å" /> '''Crystal structure of ...) |
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==Overview== | ==Overview== | ||
| - | Malaria is caused by protozoan erythrocytic parasites of the Plasmodium | + | Malaria is caused by protozoan erythrocytic parasites of the Plasmodium genus, with Plasmodium falciparum being the most dangerous and widespread disease-causing species. Falcipain-2 (FP-2) of P. falciparum is a papain-family (C1A) cysteine protease that plays an important role in the parasite life cycle by degrading erythrocyte proteins, most notably hemoglobin. Inhibition of FP-2 and its paralogues prevents parasite maturation, suggesting these proteins may be valuable targets for the design of novel antimalarial drugs, but lack of structural knowledge has impeded progress toward the rational discovery of potent, selective, and efficacious inhibitors. As a first step toward this goal, we present here the crystal structure of mature FP-2 at 3.1 A resolution, revealing novel structural features of the FP-2 subfamily proteases including a dynamic beta-hairpin hemoglobin binding motif, a flexible N-terminal alpha-helical extension, and a unique active-site cleft. We also demonstrate by biochemical methods that mature FP-2 can proteolytically process its own precursor in trans at neutral to weakly alkaline pH, that the binding of hemoglobin to FP-2 is strictly pH-dependent, and that FP-2 preferentially binds methemoglobin over hemoglobin. Because the specificity and proteolytic activity of FP-2 toward its multiple targets appears to be pH-dependent, we suggest that environmental pH may play an important role in orchestrating FP-2 function over the different life stages of the parasite. Moreover, it appears that selectivity of FP-2 for methemoglobin may represent an evolutionary adaptation to oxidative stress conditions within the host cell. |
==About this Structure== | ==About this Structure== | ||
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[[Category: Hogg, T.]] | [[Category: Hogg, T.]] | ||
[[Category: Nagarajan, K.]] | [[Category: Nagarajan, K.]] | ||
| - | [[Category: Schmidt, C | + | [[Category: Schmidt, C L.]] |
[[Category: alpha helix]] | [[Category: alpha helix]] | ||
[[Category: l-domain]] | [[Category: l-domain]] | ||
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[[Category: twisted antiparallel beta-sheet]] | [[Category: twisted antiparallel beta-sheet]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:31:51 2008'' |
Revision as of 15:31, 21 February 2008
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Crystal structure of falcipain-2 from Plasmodium falciparum
Overview
Malaria is caused by protozoan erythrocytic parasites of the Plasmodium genus, with Plasmodium falciparum being the most dangerous and widespread disease-causing species. Falcipain-2 (FP-2) of P. falciparum is a papain-family (C1A) cysteine protease that plays an important role in the parasite life cycle by degrading erythrocyte proteins, most notably hemoglobin. Inhibition of FP-2 and its paralogues prevents parasite maturation, suggesting these proteins may be valuable targets for the design of novel antimalarial drugs, but lack of structural knowledge has impeded progress toward the rational discovery of potent, selective, and efficacious inhibitors. As a first step toward this goal, we present here the crystal structure of mature FP-2 at 3.1 A resolution, revealing novel structural features of the FP-2 subfamily proteases including a dynamic beta-hairpin hemoglobin binding motif, a flexible N-terminal alpha-helical extension, and a unique active-site cleft. We also demonstrate by biochemical methods that mature FP-2 can proteolytically process its own precursor in trans at neutral to weakly alkaline pH, that the binding of hemoglobin to FP-2 is strictly pH-dependent, and that FP-2 preferentially binds methemoglobin over hemoglobin. Because the specificity and proteolytic activity of FP-2 toward its multiple targets appears to be pH-dependent, we suggest that environmental pH may play an important role in orchestrating FP-2 function over the different life stages of the parasite. Moreover, it appears that selectivity of FP-2 for methemoglobin may represent an evolutionary adaptation to oxidative stress conditions within the host cell.
About this Structure
2GHU is a Single protein structure of sequence from Plasmodium falciparum. Full crystallographic information is available from OCA.
Reference
Structural and functional characterization of Falcipain-2, a hemoglobinase from the malarial parasite Plasmodium falciparum., Hogg T, Nagarajan K, Herzberg S, Chen L, Shen X, Jiang H, Wecke M, Blohmke C, Hilgenfeld R, Schmidt CL, J Biol Chem. 2006 Sep 1;281(35):25425-37. Epub 2006 Jun 15. PMID:16777845
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