2aae

THE ROLE OF HISTIDINE-40 IN RIBONUCLEASE T1 CATALYSIS: THREE-DIMENSIONAL STRUCTURES OF THE PARTIALLY ACTIVE HIS40LYS MUTANT

spinqualitylabelsall models 2aae, resolution 1.80Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2aae is a 1 chain structure with sequence from Aspergillus oryzae. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: CA, PO4 Activity: Ribonuclease T(1), with EC number 3.1.27.3 Resources: FirstGlance, OCA, RCSB, PDBsum 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 PubMed Histidine-40 is known to participate in phosphodiester transesterification catalyzed by the enzyme ribonuclease T1. A mutant enzyme with a lysine replacing the histidine-40 (His40Lys RNase T1) retains considerable catalytic activity [Steyaert, J., Hallenga, K., Wyns, L., & Stanssens, P. (1990) Biochemistry 29, 9064-9072]. We report on the crystal structures of His40Lys RNase T1 containing a phosphate anion and a guanosine 2'-phosphate inhibitor in the active site, respectively. Similar to previously described structures, the phosphate-containing crystals are of space group P2(1)2(1)2(1), with one molecule per asymmetric unit (a = 48.27 A, b = 46.50 A, c = 41.14 A). The complex with 2'-GMP crystallized in the lower symmetry space group P2(1), with two molecules per asymmetric unit (a = 49.20 A, b = 48.19 A, c = 40.16 A, beta = 90.26). The crystal structures have been solved at 1.8- and 2.0-A resolution yielding R values of 14.5% and 16.0%, respectively. Comparison of these His40Lys structures with the corresponding wild-type structures, containing 2'-GMP [Arni, R., Heinemann, U., Tokuoka, R., & Saenger, W. (1988) J. Biol. Chem. 263, 15358-15368] and vanadate [Kostrewa, D., Hui-Woog Choe, Heinemann, U., & Saenger, W. (1989) Biochemistry 28, 7692-7600] in the active site, respectively, leads to the following conclusions. First, the His40Lys mutation causes no significant changes in the overall structure of RNase T1; second, the Lys40 side chains in the mutant structures occupy roughly the same space as His40 in the corresponding wild-type RNase T1 structures.(ABSTRACT TRUNCATED AT 250 WORDS) Role of histidine-40 in ribonuclease T1 catalysis: three-dimensionalstructures of the partially active His40Lys mutant.,Zegers I, Verhelst P, Choe HW, Steyaert J, Heinemann U, Saenger W, Wyns L Biochemistry. 1992 Nov 24;31(46):11317-25. PMID:1445870 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Ribonuclease

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