Detailed Structure–Function Correlations of Bacillus subtilis Acetolactate Synthase. Issue 1 (13th November 2014)

• Record Type: Journal Article
• Authors: Sommer, Bettina; von Moeller, Holger; Haack, Martina; Qoura, Farah; Langner, Clemens; Bourenkov, Gleb; Garbe, Daniel; Loll, Bernhard; Brück, Thomas
• Is Part Of: Chembiochem. Volume 16:Issue 1(2015)
• Page Start: 110
• Page End: 118
• Publication Date: 2014-11-13
• Subjects: Biochemistry -- Periodicals; Molecular biology -- Periodicals; Pharmaceutical chemistry -- Periodicals; 572
• DOI: 10.1002/cbic.201402541
• Languages: English
• ISSNs: 1439-4227

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Isobutanol is deemed to be a next‐generation biofuel and a renewable platform chemical.<xref ref-type="link" rid="bib1">1</xref> Non‐natural biosynthetic pathways for isobutanol production have been implemented in cell‐based and in vitro systems with <italic>Bacillus subtilis</italic> acetolactate synthase (AlsS) as key biocatalyst.<xref ref-type="link" rid="bib2">2</xref>–<xref ref-type="link" rid="bib6">6</xref> 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 Å 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.</p> </abstract>