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The Conservation of Structure and Mechanism of Catalytic Action in a Family of Thiamin Pyrophosphate (TPP)-dependent EnzymesThiamin pyrophosphate (TPP)-dependent enzymes are a divergent family of TPP and metal ion binding proteins that perform a wide range of functions with the common decarboxylation steps of a -(O=)C-C(OH)- fragment of alpha-ketoacids and alpha- hydroxyaldehydes. To determine how structure and catalytic action are conserved in the context of large sequence differences existing within this family of enzymes, we have carried out an analysis of TPP-dependent enzymes of known structures. The common structure of TPP-dependent enzymes is formed at the interface of four alpha/beta domains from at least two subunits, which provide for two metal and TPP-binding sites. Residues around these catalytic sites are conserved for functional purpose, while those further away from TPP are conserved for structural reasons. Together they provide a network of contacts required for flip-flop catalytic action within TPP-dependent enzymes. Thus our analysis defines a TPP-action motif that is proposed for annotating TPP-dependent enzymes for advancing functional proteomics.
Document ID
Document Type
Preprint (Draft being sent to journal)
Dominiak, P. (NASA Marshall Space Flight Center Huntsville, AL, United States)
Ciszak, Ewa (NASA Marshall Space Flight Center Huntsville, AL, United States)
Date Acquired
August 22, 2013
Publication Date
January 1, 2004
Subject Category
Inorganic, Organic and Physical Chemistry
Distribution Limits
Work of the US Gov. Public Use Permitted.