NAD Biosynthesis Evolution in Bacteria: Lateral Gene Transfer of Kynurenine Pathway in Xanthomonadales and Flavobacteriales

Autor(es)

Lima, Wanessa C. ^[1] ; Varani, Alessandro M. ^[2] ; Menck, Carlos F. M. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Biomed Sci, Dept Microbiol, Sao Paulo - Brazil

^[2] Univ Sao Paulo, Inst Biosci, Dept Bot, Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Molecular Biology and Evolution; v. 26, n. 2, p. 399-406, Feb. 2009.
• Área do conhecimento: Ciências Biológicas - Genética
• Citações Web of Science: 27
• Assunto(s): Bactérias Xanthomonas Bacteroidetes Flavobacterium Aminoácidos Triptofano Cinurenina

Resumo

The biosynthesis of quinolinate, the de novo precursor of nicotinamide adenine dinucleotide (NAD), may be performed by two distinct pathways, namely, the bacterial aspartate (aspartate-to-quinolinate) and the eukaryotic kynurenine (tryptophan-to-quinolinate). Even though the separation into eukaryotic and bacterial routes is long established, recent genomic surveys have challenged this view, because certain bacterial species also carry the genes for the kynurenine pathway. In this work, both quinolinate biosynthetic pathways were investigated in the Bacteria clade and with special attention to Xanthomonadales and Bacteroidetes, from an evolutionary viewpoint. Genomic screening has revealed that a small number of bacterial species possess some of the genes for the kynurenine pathway, which is complete in the genus Xanthomonas and in the order Flavobacteriales, where the aspartate pathway is absent. The opposite pattern (presence of the aspartate pathway and absence of the kynurenine pathway) in close relatives(Xylella ssp. and the order Bacteroidales, respectively) points to the idea of a recent acquisition of the kynurenine pathway through lateral gene transfer in these bacterial groups. In fact, sequence similarity comparison and phylogenetic reconstruction both suggest that at least part of the genes of the kynurenine pathway in Xanthomonas and Flavobacteriales is shared by eukaryotes. These results reinforce the idea of the role that lateral gene transfer plays in the configuration of bacterial genomes, thereby providing alternative metabolic pathways, even with the replacement of primary and essential cell functions, as exemplified by NAD biosynthesis. (AU)

• Processo FAPESP: 07/54628-0 - Potêncialização de agentes quimioterápicos através de siRNA para silenciamento de processos de reparo de DNA
• Beneficiário: Carlos Frederico Martins Menck
• Linha de fomento: Auxílio à Pesquisa - Regular