New small-molecule alcohol synthesis by breaking the space limitation of the aromatic cage in Pseudomonas sp. AK1 BBOX

Fe(ii)/2OG-dependent oxygenase & gamma;-butyrobetaine hydroxylase (BBOX) stereoselectively hydroxylates inactive C-H bonds and produces l-carnitine. It has potential applications in the biosynthesis of l-carnitine and the synthesis of other small molecule alcohols. In this paper, we systematically explore the substrate range of Pseudomonas sp. AK1 BBOX (psBBOX), with emphasis on the quaternary ammonium portion of & gamma;-butyrobetaine (& gamma;-BB). The space limitation of the aromatic cage in psBBOX in the hydroxylation of large quaternary ammonium analogues was studied, and the role of four aromatic amino acid residues in the substrate binding mode was analyzed. Consequently, the F188A mutant was developed with the ability to hydroxylate cyclic quaternary ammonium analogues and generate new alcohol compounds by breaking the limitation of the aromatic cage.

Automated summary

This paper investigates the substrate range of Pseudomonas sp. AK1 BBOX (psBBOX) and analyzes the role of aromatic amino acid residues in substrate binding mode. Through the study, a F188A mutant is developed that can hydroxylate cyclic quaternary ammonium analogues and generate new alcohol compounds by breaking the limitation of aromatic cage.