No abstract

No abstract

Benzaldehyde lyase (BAL; EC 4.1.2.38) is a thiamine diphosphate (ThDP) dependent enzyme that catalyses the enantioselective carboligation of two molecules of benzaldehyde to form (R)-benzoin. BAL has hence aroused interest for its potential in the industrial synthesis of optically active benzoins and derivatives. The structure of BAL was previously solved to a resolution of 2.6 Å using MAD experiments on a selenomethionine derivative [Mosbacher et al. (2005), FEBS J. 272, 6067-6076]. In this communication of parallel studies, BAL was crystallized in an alternative space group (P2 1 2 1 2 1) and its structure refined to a resolution of 1.65 Å , allowing detailed observation of the water structure, active-site interactions with ThDP and also the electron density for the co-solvent 2-methyl-2,4-pentanediol (MPD) at hydrophobic patches of the enzyme surface.

The search for new enzymes is facilitated by the rapidly growing number of genome sequences from different organisms. However, the discovery of functional proteins is still time intensive and complex alignments have to be performed. Herein, a genome database search identified a new, until now undescribed, putative lipase from Pseudomonas stutzeri strain A1501. The gene was cloned and expressed as functional protein in E. coli. A biochemical characterization provided an indication that the enzyme could be classified as an esterase with an alkaline pH optimum and a temperature optimum at 50˚C. The enzyme was able to perform the kinetic resolution of racemic esters and could therefore be an interesting candidate for chiral synthesis.

No abstract