Mechanistic implications from structures of yeast alcohol dehydrogenase complexed with coenzyme and an alcohol

Abstract

Yeast alcohol dehydrogenase I is a homotetramer of subunits with 347 amino acid residues, catalyzing the oxidation of alcohols using NAD(+) as coenzyme. A new X-ray structure was determined at 3.0 Å where both subunits of an asymmetric dimer bind coenzyme and trifluoroethanol. The tetramer is a pair of back-to-back dimers. Subunit A has a closed conformation and can represent a Michaelis complex with an appropriate geometry for hydride transfer between coenzyme and alcohol, with the oxygen of 2,2,2-trifluoroethanol ligated at 2.1 Å to the catalytic zinc in the classical tetrahedral coordination with Cys-43, Cys-153, and His-66. Subunit B has an open conformation, and the coenzyme interacts with amino acid residues from the coenzyme binding domain, but not with residues from the catalytic domain. Coenzyme appears to bind to and dissociate from the open conformation. The catalytic zinc in subunit B has an alternative, inverted coordination with Cys-43, Cys-153, His-66 and the carboxylate of Glu-67, while the oxygen of trifluoroethanol is 3.5 Å from the zinc. Subunit B may represent an intermediate in the mechanism after coenzyme and alcohol bind and before the conformation changes to the closed form and the alcohol oxygen binds to the zinc and displaces Glu-67.

A Self‐Powered Ethanol Biosensor

“…The latter is electrically wired in a direct‐electron‐transfer regime via a MWCNT‐functionalized graphite electrode. Enzyme structures were taken from the RCSB protein data bank (PDB); ADH: 5ENV, AOx: 5I68, and HRP: 1W4W …”

Interpreting the Collision Cross Sections of Native-like Protein Ions: Insights from Cation-to-Anion Proton-Transfer Reactions

“…Ω for serum albumin (PDB: 4F5S), 43 streptavidin (PDB: 4Y5D), 44 avidin (PDB: 1AVD), 45 and alcohol dehydrogenase (PDB: 5ENV) 46 were calculated using the projection approximation 47 and exact hard-sphere scattering 48 methods as implemented in EHSS2/k. 49 Prior to the Ω calculations, all noncovalent additions to the protein(s) in the deposited structures, including water molecules and metal ions, were deleted and Chimera 50 was used to complete side chains and add hydrogen atoms.…”

Biotransformation of green tea (Camellia sinensis) by wine yeast Saccharomyces cerevisiae

“…Geraniol and linalool in green tea also exist in glycoside forms (Ho et al, 2015), which can be released by yeast glycosidases. Geraniol can also be catalyzed by yeast alcohol dehydrogenase with NAD + to form geranial, the latter can be oxidized enzymatically and/or chemically into geranic acid (Marmulla, Cala, Markert, Schweder, & Harder, 2016;Plapp, Charlier, & Ramaswamy, 2016). Such dynamic changes of geraniol and linalool were likely the results of interconversion and enzyme reactions that occurred in yeast.…”