Poster #RP210
Molecular Modeling of Plant Alcohol Dehydrogenases
Claudia Elizabeth Thompson*, Loreta Brandão Freitas*, Francisco Mauro Salzano*, Osmar Norberto de Souza**
*Universidade Federal do Rio Grande do Sul, Porto Alegre, Brasil; **Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brasil
The alcohol dehydrogenase (Adh) genes encode glycolytic enzymes that have been characterized in some plant families. Although the amino acid sequences of zinc-containing long-chain (LC) ADHs are highly conserved, the metabolic function of this enzyme is variable. Besides this, they have different patterns of expression and are submitted to differences in nonsynonymous substitution rates between gene copies. Despite the large number of studies involving the Adh gene family, there does not exist a wide ranging study correlating molecular evolution and structural biology of the plant alcohol dehydrogenases. Moreover, this is the first study where a plant ADH tridimensional structure is proposed and where the birth-and-death process is used to explain the molecular evolution of this multigene family. The coefficients of functional divergence estimated between the Adh1 and Adh2 gene groups indicate statistically significant site-specific shift of evolutionary rate between them, as well as between those of different botanical families, suggesting that altered functional constraints may take place at some amino acid residues after speciation. Theoretical tridimensional models of seventeen plant alcohol dehydrogenase were constructed and verified to be stereochemically valid. The amino acids residues important for the functional divergence of this enzyme were identified in the ADH tridimensional structure.