LOVely enzymes - towards engineering light-controllable biocatalysts.
Bottom Line: Light control over enzyme function represents a novel and exciting field of biocatalysis research.Blue-light photoreceptors of the Light, Oxygen, Voltage (LOV) family have recently been investigated for their applicability as photoactive switches.We discuss here the primary photochemical events leading to light activation of LOV domains as well as the proposed signal propagation mechanism to the respective effector domain.
Affiliation: Institute of Molecular Enzyme Technology, Heinrich-Heine-University Duesseldorf, Research Centre Juelich, D-52426-Juelich, Germany.Show MeSH
Related in: MedlinePlus
Mentions: Thus far, just a single example exists which demonstrates light‐dependent control over a completely sensor‐unrelated protein. Here, the extensively characterized enzyme, dihydrofolate reductase (DHFR) from E. coli, was used as target effector module to be engineered with a plant LOV domain allowing for allosteric control over DHFR biocatalytic activity (Lee et al., 2008). DHFR is an enzyme that catalyses the reduction of 5,6‐dihydrofolate (DHF) to 5,6,7,8‐tetrahydrofolate (THF) using NADPH as a cofactor. The enzyme plays a central role to maintain the cellular levels of tetrahydrofolate and its derivatives which are essential for purine and thymidylate biosynthesis. Therefore, this enzyme has been an important target for the development of antibacterial agents, anti‐cancer drugs and other therapeutics (Volpato and Pelletier, 2009). It also serves as an important system for understanding the mechanism of enzyme catalysis. Extensive kinetic studies of E. coli DHFR and various mutants along with X‐ray crystallography, NMR spectroscopy and computational studies have revealed the correlation between protein dynamics and catalytic function (Sawaya and Kraut, 1997; Schnell et al., 2004; Hammes‐Schiffer and Benkovic, 2006) and provided evidence for a network of coupled motions. Figure 3A depicts the structure of DHFR showing the ligand binding site as well as the location of important loop regions that are involved in enzyme catalysis.
Affiliation: Institute of Molecular Enzyme Technology, Heinrich-Heine-University Duesseldorf, Research Centre Juelich, D-52426-Juelich, Germany.