| Literature DB >> 22974724 |
Xiang Liu1, Sabine Bastian, Christopher D Snow, Eric M Brustad, Tatyana E Saleski, Jian-He Xu, Peter Meinhold, Frances H Arnold.
Abstract
We have determined the X-ray crystal structures of the NADH-dependent alcohol dehydrogenase LlAdhA from Lactococcus lactis and its laboratory-evolved variant LlAdhA(RE1) at 1.9Å and 2.5Å resolution, respectively. LlAdhA(RE1), which contains three amino acid mutations (Y50F, I212T, and L264V), was engineered to increase the microbial production of isobutanol (2-methylpropan-1-ol) from isobutyraldehyde (2-methylpropanal). Structural comparison of LlAdhA and LlAdhA(RE1) indicates that the enhanced activity on isobutyraldehyde stems from increases in the protein's active site size, hydrophobicity, and substrate access. Further structure-guided mutagenesis generated a quadruple mutant (Y50F/N110S/I212T/L264V), whose KM for isobutyraldehyde is ∼17-fold lower and catalytic efficiency (kcat/KM) is ∼160-fold higher than wild-type LlAdhA. Combining detailed structural information and directed evolution, we have achieved significant improvements in non-native alcohol dehydrogenase activity that will facilitate the production of next-generation fuels such as isobutanol from renewable resources.Entities:
Mesh：
Substances：
Year: 2012 PMID： 22974724 PMCID： PMC3542407 DOI： 10.1016/j.jbiotec.2012.08.008
Source DB: PubMed Journal: J Biotechnol ISSN： 0168-1656 Impact factor: 3.307