The role of conformational flexibility in Baeyer-Villiger monooxygenase catalysis and structure.
Biochim Biophys Acta
; 1864(12): 1641-1648, 2016 12.
Article
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| MEDLINE
| ID: mdl-27570148
ABSTRACT
BACKGROUND:
The Baeyer-Villiger monooxygenases (BMVOs) are a group of microbial enzymes that have garnered interest as industrial biocatalysts. While great strides have been made in recent years to understand the mechanism of these enzymes from a structural perspective, our understanding remains incomplete. In particular, the role of a twenty residue loop (residues 487-504), which we refer to as the "Control Loop," that is observed in either an ordered or disordered state in various crystal structures remains unclear.METHODS:
Using SAXS, we have made the first observations of the Loop in solution with two BVMOs, cyclohexanone monooxygenase (CHMO) and cyclopentadecanone monooxygenase. We also made a series of mutants of CHMO and analyzed them using SAXS, ITC, and an uncoupling assay.RESULTS:
These experiments show that Control Loop ordering results in an overall more compact enzyme without altering global protein foldedness. We have also demonstrated that the Loop plays a critical and complex role on enzyme structure and catalysis. The Control Loop appears to have a direct impact on the organization of the overall structure of the protein, as well as in influencing the active site environment.CONCLUSIONS:
The data imply that the Loop can be divided into two regions, referred to as "sub-loops," that coordinate overall domain movements to changes in the active site. GENERALSIGNIFICANCE:
A better understanding of the mechanistic role of the Control Loop may ultimately be helpful in designing mutants with altered specificity and improved catalytic efficiency.Palabras clave
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MEDLINE
Asunto principal:
Oxigenasas de Función Mixta
Idioma:
En
Revista:
Biochim Biophys Acta
Año:
2016
Tipo del documento:
Article