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Publication Abstract from PubMed

PFTA (Pyrococcus furiosus thermostable amylase) is a hyperthermophilic amylase isolated from the archaeon Pyrococcus furiosus. This enzyme possesses characteristics of both alpha-amylase- and cyclodextrin (CD)-hydrolyzing enzymes, allowing it to degrade pullulan, CD and acarbose-activities that are absent in most alpha-amylases-without the transferring activity that is common in CD-hydrolyzing enzymes. The crystal structure of PFTA revealed a unique monomeric subunit with an extended N-terminal region and an N'-domain folded into its own active site-a significantly altered domain configuration relative to that of the conventional dimeric CD-hydrolyzing amylases in glycoside hydrolase family 13. The active site is formed by the interface of the N'-domain and the catalytic domain and exhibits a broad and wide-open geometry without the concave pocket that is commonly found in the active sites of maltogenic amylases. The mutation of a residue (Gly415 to Glu) located at the domain interface between the N'- and catalytic domains yielded an enzyme that produced a significantly higher purity maltoheptaose (G7) from beta-CD, supporting the involvement of this interface in substrate recognition and indicating that this mutant enzyme is a suitable candidate for the production of pure G7. The unique configuration of the active site distinguishes this archaic monomeric enzyme from classical bacterial CD-hydrolyzing amylases and provides a molecular basis for its enzymatic characteristics and for its potential use in industrial applications.

A novel domain arrangement in a monomeric cyclodextrin-hydrolyzing enzyme from the hyperthermophile Pyrococcus furiosus.,Park JT, Song HN, Jung TY, Lee MH, Park SG, Woo EJ, Park KH Biochim Biophys Acta. 2013 Jan;1834(1):380-6. doi: 10.1016/j.bbapap.2012.08.001. , Epub 2012 Aug 8. PMID:22902546^[1]

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