Structural and Functional Characterization of a Novel Aldolase-Dehydratase
Mentor 1
Dr. Nick Silavggi
Location
Union Wisconsin Room
Start Date
24-4-2015 10:30 AM
End Date
24-4-2015 11:45 AM
Description
One of the primary advantages of enzymes over traditional catalysts—their extreme specificity—is also a liability. Limited substrate specificity has proven to be a significant barrier to the wide-spread application of enzymes in organic synthesis. While engineering known enzymes to alter substrate specificity has been effective in a number of cases, identifying new enzymes with unique reaction and/or substrate specificity is also an important factor in the quest for viable biocatalysts for green chemistry. To this end, we have begun characterizing enzymes from the acetoacetate decarboxylase-like superfamily (ADCSF), a large and virtually unexplored family of enzymes with members in most bacterial lineages. Bioinformatic analysis has identified seven distinct families within the ADCSF. Our structural and functional characterization of an ADCSF Family V enzyme from Streptomyces bingchenggensis (SbAD) shows that its structure almost identical to that of the prototypical ADCSF enzyme, Clostridium acetobutylicum acetoacetate decarboxylase (ADC), despite the fact that SbAD is not a decarboxylase. The structures of SbAD in unliganded and substrate-bound forms, together with steady state kinetics studies, have revealed that SbAD is a pyruvate aldolase-dehydratase. In all, these studies suggest that there is significant diversity in the ADCSF in both reaction and substrate specificity. Thus, the ADCSF may be a rich and under-utilized source of biocatalysts.
Structural and Functional Characterization of a Novel Aldolase-Dehydratase
Union Wisconsin Room
One of the primary advantages of enzymes over traditional catalysts—their extreme specificity—is also a liability. Limited substrate specificity has proven to be a significant barrier to the wide-spread application of enzymes in organic synthesis. While engineering known enzymes to alter substrate specificity has been effective in a number of cases, identifying new enzymes with unique reaction and/or substrate specificity is also an important factor in the quest for viable biocatalysts for green chemistry. To this end, we have begun characterizing enzymes from the acetoacetate decarboxylase-like superfamily (ADCSF), a large and virtually unexplored family of enzymes with members in most bacterial lineages. Bioinformatic analysis has identified seven distinct families within the ADCSF. Our structural and functional characterization of an ADCSF Family V enzyme from Streptomyces bingchenggensis (SbAD) shows that its structure almost identical to that of the prototypical ADCSF enzyme, Clostridium acetobutylicum acetoacetate decarboxylase (ADC), despite the fact that SbAD is not a decarboxylase. The structures of SbAD in unliganded and substrate-bound forms, together with steady state kinetics studies, have revealed that SbAD is a pyruvate aldolase-dehydratase. In all, these studies suggest that there is significant diversity in the ADCSF in both reaction and substrate specificity. Thus, the ADCSF may be a rich and under-utilized source of biocatalysts.
