1h1h
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CRYSTAL STRUCTURE OF EOSINOPHIL CATIONIC PROTEIN IN COMPLEX WITH 2',5'-ADP AT 2.0 A RESOLUTION REVEALS THE DETAILS OF THE RIBONUCLEOLYTIC ACTIVE SITE
OverviewOverview
Eosinophil cationic protein (ECP) is a component of the eosinophil granule matrix. It shows marked toxicity against helminth parasites, bacteria single-stranded RNA viruses, and host epithelial cells. Secretion of human ECP is related to eosinophil-associated allergic, asthmatic, and inflammatory diseases. ECP belongs to the pancreatic ribonuclease superfamily of proteins, and the crystal structure of ECP in the unliganded form (determined previously) exhibited a conserved RNase A fold [Boix, E., et al. (1999) Biochemistry 38, 16794-16801]. We have now determined a high-resolution (2.0 A) crystal structure of ECP in complex with adenosine 2',5'-diphosphate (2',5'-ADP) which has revealed the details of the ribonucleolytic active site. Residues Gln-14, His-15, and Lys-38 make hydrogen bond interactions with the phosphate at the P(1) site, while His-128 interacts with the purine ring at the B(2) site. A new phosphate binding site, P(-)(1), has been identified which involves Arg-34. This study is the first detailed structural analysis of the nucleotide recognition site in ECP and provides a starting point for the understanding of its substrate specificity and low catalytic efficiency compared with that of the eosinophil-derived neurotoxin (EDN), a close homologue.
About this StructureAbout this Structure
1H1H is a Single protein structure of sequence from Homo sapiens with as ligand. Known structural/functional Site: . Full crystallographic information is available from OCA.
ReferenceReference
The crystal structure of eosinophil cationic protein in complex with 2',5'-ADP at 2.0 A resolution reveals the details of the ribonucleolytic active site., Mohan CG, Boix E, Evans HR, Nikolovski Z, Nogues MV, Cuchillo CM, Acharya KR, Biochemistry. 2002 Oct 8;41(40):12100-6. PMID:12356310
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