Structural studies of wild-type and Val120Thr mutant candida boidinii formate dehydrogenase

Candida boidinii NAD+-dependent formate dehydrogenase (CbFDH) has attracted considerable interest owing to its potential in generating biofuels and various industrial chemicals from carbon dioxide (CO2). In an endeavor to enhance its utility, this study introduces essential insights regarding the molecular structures of CbFDH variants. These insights provide details that will help our understanding of the enzyme's functional mechanisms and its inherent potential for protein engineer- ing. Employing advanced methodologies at the Turkish Light Source "Turkish DeLight", the atomic X-ray crystal structures of both the wild-type CbFDH and the Val120Thr mutant were determined. These structures were obtained at different temperatures, cryogenic and ambient, thereby offering a holistic comprehension of the enzyme's dynamics under diverse environmental settings. A key aspect of importance centers around the newly discovered hydrogen bonds within the active site of the Val120Thr mutant. The formation of these bonds between Thr120 and water molecules implies a potential enhancement of the active site's stability. Additionally, it suggests the likelihood of an improved electron transfer during the enzymatic reaction. These structural differences provide a foundation for understanding the mutant's increased effectiveness in catalyzing formate conversion — a characteristic with significant promise for industrial applications. It is important to note that while these structural observations offer exciting prospects, further experimental data are required to validate the hypothesized mechanisms. Co-crystallization with the coenzyme and substrate has the potential to offer further insights, allowing a comprehensive understanding of the role of the identified hydrogen bonds in enhancing CbFDH's capabilities. In conclusion, the knowledge gained from the X-ray crystal structures of CbFDH in its wild-type and Val120Thr mutant forms, provides a foundation for future advancements in the field of protein engineering. As researchers delve further into the functional implications of the observed structural changes, the potential for harnessing CbFDH's catalytic abilities in biotechnological applications becomes increasingly feasible. This study highlights the dynamic relationship between structural insights and practical applications, underscoring the exciting possibilities for optimizing enzymatic processes in service of a more sustainable future.