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Publication Abstract from PubMed

The D-aldohexose dehydrogenase from the thermoacidophilic archaeon Thermoplasma acidophilum (AldT) is a homotetrameric enzyme that catalyzes the oxidation of several D-aldohexoses, especially D-mannose. AldT comprises a unique C-terminal tail motif (residues 247-255) that shuts the active-site pocket of the neighboring subunit. The functional role of the C-terminal tail of AldT has been investigated using mutational and crystallographic analyses. A total of four C-terminal deletion mutants (Delta254, Delta253, Delta252, and Delta249) and two site-specific mutants (Y86G and P254G) were expressed by Escherichia coli and purified. Enzymatic characterization of these mutants revealed that the C-terminal tail is a requisite and that the interaction between Tyr86 and Pro254 is critical for enzyme activity. The crystal structure of the Delta249 mutant was also determined. The structure showed that the active-site loops undergo a significant conformational change, which leads to the structural deformation of the substrate-binding pocket. Proteins 2009. (c) 2008 Wiley-Liss, Inc.

C-terminal tail derived from the neighboring subunit is critical for the activity of Thermoplasma acidophilumD-aldohexose dehydrogenase.,Nishioka T, Yasutake Y, Nishiya Y, Tamura N, Tamura T Proteins. 2008 Oct 21. PMID:19089950^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.