Old Yellow Enzyme‐Catalyzed Dehydrogenation of Saturated Ketones

Abstract

Enzymes from extremophiles have always been of great interest for biotechnology because of their ruggedness against various stress factors. We have isolated, cloned, heterologously expressed and characterized a thermostable old yellow enzyme (OYE) from Geobacillus kaustophilus. In addition to the expected enone reduction, GkOYE also catalyzes the reverse reaction, i.e., the desaturation of C À C bonds adjacent to a carbonyl to give the corresponding a,b-unsaturated ketone. The reaction proceeds at the expense of molecular oxygen without the need for a nicotinamide cofactor and represents an environmentally benign alternative to known chemical dehydrogenation methods.

Identification and characterization of a novel “thermophilic-like” Old Yellow Enzyme from the genome of Chryseobacterium sp. CA49

“…However, characterized members of the "thermophilic-like" subfamily are evidently much fewer although they are not restricted to thermophilic origins. To the best of our knowledge, TOYE, CrS and GkOYE are the only three thermophilic counterparts that has been characterized [20,21,38], while other "thermophilic-like" OYEs are from mesophilic organism with moderate temperature optima [3,39], same as Chr-OYE3 in the present study. The enzyme shares the conserved residues involved in catalytic activity, FMN binding, substrate binding and subunits interaction within this subfamily.…”

“…Subsequently, three thermostable OYEs from thermophilic organisms have been proved to be members in this subfamily [3,13,20,21]. They are CrS from Thermus scotoductus SA-01, GkOYE from Geobacillus kaustophilus and TOYE from Thermoanaerobacter pseudethanolicus E39.…”

Old Yellow Enzyme-Catalysed Asymmetric Hydrogenation: Linking Family Roots with Improved Catalysis

“…A remarkable property observed for class III OYEs is their occurrence in solution as homodimers and homotetramers [22,76,105]. Even higher species as octamers and dodecamers, emerged from functional homodimers, were observed for TOYE and TsOYE [77,79].…”

“…Nevertheless, the enzymes AtOPR1-AtOPR3 from Arabidopsis thaliana [65,66], and LeOPR1-LeOPR3 from Solanum lycopersicum (tomato) [67,68], were characterised according to their structure, function and physiological role. Two thirds of the characterised OYEs have been obtained from various classes of bacteria including proteobacteria (28%) [69,70], actinobacteria (5%) [22,71,72], bacteroidetes (5%) [73,74], firmicutes (10%) [75][76][77], deinococcus-thermus (3%) [78][79][80], and cyanobacteria (17%) [21,81].…”

Enzyme-substrate matching in biocatalysis: in silico studies to predict substrate preference of ten putative ene-reductases from Mucor circinelloides MUT44

“…For McOYE10, the templates used were the thermostable OYE from Thermoanaerobacter pseudethanolicus E39 (PDB ID 3KRU) [24], Thermus scotoductus SA-01 (PDB ID 3HF3) [25], YqjM from Bacillus subtilis (PDB ID 1Z41) [26], OYE from Geobacillus kaustophilus (PDB ID 3GR7) [27] and the xenobiotic reductase A from Pseudomonas putida 86 (PDB ID 2H8X) [28]. Thus, for McOYE10, the best structural homologs were all bacterial enzymes.…”