title: Crystal structure of a ternary complex of the alcohol dehydrogenase from Sulfolobus solfataricus.
abstract: The crystal structure of a ternary complex of the alcohol dehydrogenase from the archaeon Sulfolobus solfataricus (SsADH) has been determined at 2.3 A. The asymmetric unit contains a dimer with a NADH and a 2-ethoxyethanol molecule bound to each subunit. The comparison with the apo structure of the enzyme reveals that this medium chain ADH undergoes a substantial conformational change in the apo-holo transition, accompanied by loop movements at the domain interface. The extent of domain closure is similar to that observed for the classical horse liver ADH, although some differences are found which can be related to the different oligomeric states of the enzymes. Compared to its apo form, the SsADH ternary complex shows a change in the ligation state of the active site zinc ion which is no longer bound to Glu69, providing additional evidence of the dynamic role played by the conserved glutamate residue in ADHs. In addition, the structure presented here allows the identification of the substrate site and hence of the residues that are important in the binding of both the substrate and the coenzyme.
authors.affiliation: Istituto di Biostrutture e Bioimmagini, CNR, via Mezzocannone 6-8, I-80134 Napoli, Italy.
authors.forename: Luciana
authors.initials: L
authors.lastname: Esposito
authors.forename: Ilaria
authors.initials: I
authors.lastname: Bruno
authors.forename: Filomena
authors.initials: F
authors.lastname: Sica
authors.forename: Carlo Antonio
authors.initials: CA
authors.lastname: Raia
authors.forename: Antonietta
authors.initials: A
authors.lastname: Giordano
authors.forename: Mosè
authors.initials: M
authors.lastname: Rossi
authors.forename: Lelio
authors.initials: L
authors.lastname: Mazzarella
authors.forename: Adriana
authors.initials: A
authors.lastname: Zagari
mesh_terms: D000426:Alcohol Dehydrogenase / Q000737:chemistry*; D001051:Apoenzymes / Q000737:chemistry; D019843:Archaeal Proteins / Q000737:chemistry*; D001665:Binding Sites; D020134:Catalytic Domain; D003460:Crystallization; D018360:Crystallography, X-Ray; D019281:Dimerization; D020035:Holoenzymes / Q000737:chemistry; D009243:NAD / Q000737:chemistry; D011485:Protein Binding; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D013050:Spectrometry, Fluorescence; D013379:Substrate Specificity; D016944:Sulfolobus / Q000201:enzymology*
chemical_list: D001051:Apoenzymes; D019843:Archaeal Proteins; D020035:Holoenzymes; D009243:NAD; D000426:Alcohol Dehydrogenase