PDBsum entry 1w8o

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Hydrolase PDB id
Protein chain
601 a.a.
GOL ×4
Waters ×709

References listed in PDB file
Key reference
Title Contribution of the active site aspartic acid to catalysis in the bacterial neuraminidase from micromonospora viridifaciens.
Authors J.N.Watson, S.Newstead, V.Dookhun, G.Taylor, A.J.Bennet.
Ref. FEBS Lett, 2004, 577, 265-269. [DOI no: 10.1016/j.febslet.2004.10.016]
PubMed id 15527797
A recombinant D92G mutant sialidase from Micromonospora viridifaciens has been cloned, expressed and purified. Kinetic studies reveal that the replacement of the conserved aspartic acid with glycine results in a catalytically competent retaining sialidase that possesses significant activity against activated substrates. The contribution of this aspartate residue to the free energy of hydrolysis for natural substrates is greater than 19 kJ/mol. The three dimensional structure of the D92G mutant shows that the removal of aspartic acid 92 causes no significant re-arrangement of the active site, and that an ordered water molecule substitutes for the carboxylate group of D92.
Figure 1.
Fig. 1. Effect of temperature on the relative rates of sialidase-catalyzed hydrolysis of MU-αNeu5Ac at pH 5.25 for the wild-type enzyme ( operator ) and D92G mutant (•). Data for wild-type reproduced with permission of the American Chemical Society.
Figure 5.
Fig. 5. Superimposition of the active site residues of wild-type catalytic domain with Neu5Ac2en (PDB 1EUS) and the D92G-Neu5Ac2en complex. Residues of the wild-type structure are shown in slate and of the mutant in wheat. The hydrogen bonding interactions are drawn as green dotted lines; the interaction of Asp92 with Asp85 is shown in orange.
The above figures are reprinted by permission from the Federation of European Biochemical Societies: FEBS Lett (2004, 577, 265-269) copyright 2004.
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