2C34

Leishmania mexicana ICP

Summary for 2C34

• Entry DOI: 10.2210/pdb2c34/pdb
• NMR Information: BMRB: 6794
• Descriptor: INHIBITOR OF CYSTEINE PEPTIDASES (1 entity in total)
• Functional Keywords: icp, chagasin, cysteine peptidase, inhibitor, immunoglobulin fold
• Biological source: LEISHMANIA MEXICANA
• Total number of polymer chains: 1
• Total formula weight: 13035.05

Authors

Smith, B.O.,Picken, N.C.,Bromek, K.,Westrop, G.D.,Mottram, J.C.,Coombs, G.H. (deposition date: 2005-10-04, release date: 2005-12-21, Last modification date: 2024-05-15)

Primary citation

Smith, B.O.,Picken, N.C.,Westrop, G.D.,Bromek, K.,Mottram, J.C.,Coombs, G.H.
The Structure of Leishmania Mexicana Icp Provides Evidence for Convergent Evolution of Cysteine Peptidase Inhibitors.
J.Biol.Chem., 281:5821-, 2006

PubMed Abstract: Clan CA, family C1 cysteine peptidases (CPs) are important virulence factors and drug targets in parasites that cause neglected diseases. Natural CP inhibitors of the I42 family, known as ICP, occur in some protozoa and bacterial pathogens but are absent from metazoa. They are active against both parasite and mammalian CPs, despite having no sequence similarity with other classes of CP inhibitor. Recent data suggest that Leishmania mexicana ICP plays an important role in host-parasite interactions. We have now solved the structure of ICP from L. mexicana by NMR and shown that it adopts a type of immunoglobulin-like fold not previously reported in lower eukaryotes or bacteria. The structure places three loops containing highly conserved residues at one end of the molecule, one loop being highly mobile. Interaction studies with CPs confirm the importance of these loops for the interaction between ICP and CPs and suggest the mechanism of inhibition. Structure-guided mutagenesis of ICP has revealed that residues in the mobile loop are critical for CP inhibition. Data-driven docking models support the importance of the loops in the ICP-CP interaction. This study provides structural evidence for the convergent evolution from an immunoglobulin fold of CP inhibitors with a cystatin-like mechanism.

PubMed: 16407198
DOI: 10.1074/JBC.M510868200

Experimental method

SOLUTION NMR