3ch3
From Proteopedia
Crystal Structure Analysis of SERA5E from plasmodium falciparum
Structural highlights
FunctionSERA5_PLAF7 Plays an essential role during the asexual blood stage development by controlling the kinetics of merozoite egress from host erythrocytes (PubMed:25599609, PubMed:28683142). Specifically, prevents premature rupture of the parasitophorous vacuole and host erythrocyte membranes (PubMed:28683142).[1] [2] May prevent merozoite phagocytosis by host monocytes via interaction with host VTN at the merozoite surface (By similarity). Plays a role in parasite growth (By similarity).[UniProtKB:P69193] Protease activity is controversial (PubMed:25599609). Has been shown in a number of studies to have protease activity towards a synthetic peptide in vitro (PubMed:13679369, PubMed:24769454, PubMed:29716996). Has also been shown to lack protease activity towards a synthetic peptide in vitro (PubMed:25599609).[3] [4] [5] [6] 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 PubMedThe sera genes of the malaria-causing parasite Plasmodium encode a family of unique proteins that are maximally expressed at the time of egress of parasites from infected red blood cells. These multi-domain proteins are unique, containing a central papain-like cysteine-protease fragment enclosed between the disulfide-linked N- and C-terminal domains. However, the central fragment of several members of this family, including serine repeat antigen 5 (SERA5), contains a serine (S596) in place of the active-site cysteine. Here we report the crystal structure of the central protease-like domain of Plasmodium falciparum SERA5, revealing a number of anomalies in addition to the putative nucleophilic serine: (1) the structure of the putative active site is not conducive to binding substrate in the canonical cysteine-protease manner; (2) the side chain of D594 restricts access of substrate to the putative active site; and (3) the S(2) specificity pocket is occupied by the side chain of Y735, reducing this site to a small depression on the protein surface. Attempts to determine the structure in complex with known inhibitors were not successful. Thus, despite having revealed its structure, the function of the catalytic domain of SERA5 remains an enigma. Structural insights into the protease-like antigen Plasmodium falciparum SERA5 and its noncanonical active-site serine.,Hodder AN, Malby RL, Clarke OB, Fairlie WD, Colman PM, Crabb BS, Smith BJ J Mol Biol. 2009 Sep 11;392(1):154-65. Epub 2009 Jul 8. PMID:19591843[7] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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