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Publication Abstract from PubMed

Isobutanol is deemed to be a next-generation biofuel and a renewable platform chemical.1 Non-natural biosynthetic pathways for isobutanol production have been implemented in cell-based and in vitro systems with Bacillus subtilis acetolactate synthase (AlsS) as key biocatalyst.2-6 AlsS catalyzes the condensation of two pyruvate molecules to acetolactate with thiamine diphosphate and Mg2+ as cofactors. AlsS also catalyzes the conversion of 2-ketoisovalerate into isobutyraldehyde, the immediate precursor of isobutanol. Our phylogenetic analysis suggests that the ALS enzyme family forms a distinct subgroup of ThDP-dependent enzymes. To unravel catalytically relevant structure-function relationships, we solved the AlsS crystal structure at 2.3 A in the presence of ThDP, Mg2+ and in a transition state with a 2-lactyl moiety bound to ThDP. We supplemented our structural data by point mutations in the active site to identify catalytically important residues.

Detailed Structure-Function Correlations of Bacillus subtilis Acetolactate Synthase.,Sommer B, von Moeller H, Haack M, Qoura F, Langner C, Bourenkov G, Garbe D, Loll B, Bruck T Chembiochem. 2014 Nov 13. doi: 10.1002/cbic.201402541. PMID:25393087^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.