3CJA
Structure of Rattus norvegicus NTPDase2 in complex with calcium and AMPPNP
Summary for 3CJA
Entry DOI | 10.2210/pdb3cja/pdb |
Related | 3CJ1 3CJ7 3CJ9 |
Descriptor | Ectonucleoside triphosphate diphosphohydrolase 2, CALCIUM ION, PHOSPHOAMINOPHOSPHONIC ACID-ADENYLATE ESTER, ... (4 entities in total) |
Functional Keywords | hydrolase, alpha/beta protein, actin-like fold, alternative splicing, calcium, glycoprotein, magnesium, membrane, transmembrane |
Biological source | Rattus norvegicus (Norway rat) |
Cellular location | Membrane; Multi-pass membrane protein (Potential): O35795 |
Total number of polymer chains | 1 |
Total formula weight | 51158.22 |
Authors | Zebisch, M.,Strater, N. (deposition date: 2008-03-12, release date: 2008-04-29, Last modification date: 2024-10-30) |
Primary citation | Zebisch, M.,Strater, N. Structural insight into signal conversion and inactivation by NTPDase2 in purinergic signaling Proc.Natl.Acad.Sci.Usa, 105:6882-6887, 2008 Cited by PubMed Abstract: Cell surface-located nucleoside triphosphate diphosphohydrolases (NTPDase1, -2, -3, and -8) are oligomeric integral membrane proteins responsible for signal conversion and inactivation in extracellular nucleotide-mediated "purinergic" signaling. They catalyze the sequential hydrolysis of the signaling molecule ATP via ADP to AMP. Here we present the structure of the extracellular domain of Rattus norvegicus NTPDase2 in an active state at resolutions between 1.7 A and 2.1 A in four different forms: (i) apo form, (ii) ternary complex with the nonhydrolyzable ATP analog AMPPNP and cofactor Ca(2+), (iii) quaternary complex with Ca(2+) and bound products AMP and phosphate, and (iv) binary product complex with AMP only. Analysis of the ATP (analog) binding mode explains the importance of several residues for activity and allows suggestion of a catalytic mechanism. The carboxylate group of E165 serves as a catalytic base and activates a water molecule, which is well positioned for nucleophilic attack on the terminal phosphate. Based on analysis of the two product complex structures in which AMP adopts different conformations, a substrate binding mode for ADP hydrolysis is proposed. This allows for an understanding of how the same hydrolytic site can be engaged in ATP and ADP but not AMP hydrolysis. PubMed: 18458329DOI: 10.1073/pnas.0802535105 PDB entries with the same primary citation |
Experimental method | X-RAY DIFFRACTION (2.1 Å) |
Structure validation
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