Utilize este identificador para referenciar este registo:
https://hdl.handle.net/1822/15982
Título: | Identification of amino acid residues critical for the substrate translocation in lactate permease JEN1p of saccharomyces cerevisiae |
Autor(es): | Pessoa, Joana Sá Silva, Isabel Soares Myrianthopoulos, Vassilios Mikros, Emmanuel Diallinas, George Casal, Margarida |
Data: | 2011 |
Resumo(s): | Lactic, acetic and propionic acids have been used for many years in industrial and pharmaceutical companies. In Saccharomyces cerevisiae, Jen1p is a major monocarboxylate:H+ symporter specific primarily for lactate, pyruvate and for acetate (TC # 2.A.1.12.2) (Casal et al., 1999). A phylogenetic tree of ScJen1p homologues (Casal et al., 2008) showed the existence of two main clusters: a Jen1 group (monocarboxylate transporters) and a Jen2-like (dicarboxylate transporters). Structure-function relationships in Jen1p have been approached by using a rational mutational analysis of conserved amino acid residues (Soares-Silva et al., 2007). Analysis of the conserved sequence 379NXX[S/T]HX[S/T]QDXXXT391, located in transmembrane segment seven (TMS-VII), showed that residues N379, H383 or D387 are necessary for function and specificity, while Q386 is important for the kinetics of Jen1p-mediated transport. In this work, we rationally designed and analyzed novel mutations in conserved regions located in TMS-II, TMS-V and TMS-XI of Jen1p, which we predicted to affect Jen1p specificity (distinction between mono and dicarboxylates) and function. Among the residues studied, F270 (TMS-V) and Q498 (TMS-XI) are specificity determinants for the distinction of mono- from dicarboxylates, and N501 (TMS-XI) is critical for function. Using a model based on Jen1p similarity with the GlpT permease, we show that all polar residues critical for function within TMS-VII and TMS-XI are aligned along the protein pore and substrate docking studies reveal a potential substrate translocation trajectory consisting mostly of the polar residues genetically identified as important for function. Overall, our results constitute a first step towards the genetic manipulation of substrate specificity in the lactate/pyruvate:H+ symporter subfamily and a tool for the in silico prediction of the function of Jen1p homologues in other fungi (Soares-Silva et al., 2011). |
Tipo: | Resumo em ata de conferência |
URI: | https://hdl.handle.net/1822/15982 |
Arbitragem científica: | no |
Acesso: | Acesso aberto |
Aparece nas coleções: | DBio - Comunicações/Communications in Congresses |
Ficheiros deste registo:
Ficheiro | Descrição | Tamanho | Formato | |
---|---|---|---|---|
Identification of amino acid residues critical for the substrate translocation in lactate permease Jen1p of Saccharomyces cerevisiae.pdf | 87,5 kB | Adobe PDF | Ver/Abrir |