1slu
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RAT ANIONIC N143H, E151H TRYPSIN COMPLEXED TO A86H ECOTIN
OverviewOverview
The three-dimensional structures of complexes of trypsin N143H, E151H, bound to ecotin A86H are determined at 2.0 A resolution via X-ray, crystallography in the absence and presence of the transition metals Zn2+, Ni2+, and Cu2+. The binding site for these transition metals was, constructed by substitution of key amino acids with histidine at the, trypsin-ecotin interface in the S2'/P2' pocket. Three histidine side, chains, two on trypsin at positions 143 and 151 and one on ecotin at, position 86, anchor the metals and provide extended catalytic recognition, for substrates with His in the P2' pocket. Comparisons of the, three-dimensional structures show the different geometries that result, upon the binding of metal in the engineered tridentate site and suggest a, structural basis for the kinetics of the metal-regulated catalysis. Of the, three metals, the binding of zinc results in the most favorable binding, geometry, not dissimilar to those observed in naturally occurring zinc, binding proteins.
About this StructureAbout this Structure
1SLU is a Protein complex structure of sequences from Escherichia coli and Rattus norvegicus with CA and ACT as ligands. Active as Trypsin, with EC number 3.4.21.4 Full crystallographic information is available from OCA.
ReferenceReference
X-ray structures of a designed binding site in trypsin show metal-dependent geometry., Brinen LS, Willett WS, Craik CS, Fletterick RJ, Biochemistry. 1996 May 14;35(19):5999-6009. PMID:8634241
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