Phylogenetic analysis of erythritol catabolic loci within the Rhizobiales and Proteobacteria

Loading...
Thumbnail Image
Date
2013-02-23
Authors
Geddes, Barney A
Hausner, Georg
Oresnik, Ivan J
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract

Abstract

					Background
				
				The ability to use erythritol as a sole carbon source is not universal among
					the Rhizobiaceae. Based on the relatedness to the catabolic genes in
						Brucella it has been suggested that the eryABCD operon
					may have been horizontally transferred into Rhizobium. During work
					characterizing a locus necessary for the transport and catabolism of
					erythritol, adonitol and L-arabitol in Sinorhizobium meliloti, we
					became interested in the differences between the erythritol loci of S.
						meliloti and R. leguminosarum. Utilizing the Ortholog
					Neighborhood Viewer from the DOE Joint Genome Institute database it appeared
					that loci for erythritol and polyol utilization had distinct arrangements
					that suggested these loci may have undergone genetic rearrangements.
			
			
				
					Results
				
				A data set was established of genetic loci containing erythritol/polyol
					orthologs for 19 different proteobacterial species. These loci were analyzed
					for genetic content and arrangement of genes associated with erythritol,
					adonitol and L-arabitol catabolism. Phylogenetic trees were constructed for
					core erythritol catabolic genes and contrasted with the species phylogeny.
					Additionally, phylogenetic trees were constructed for genes that showed
					differences in arrangement among the putative erythritol loci in these
					species.
			
			
				
					Conclusions
				
				Three distinct erythritol/polyol loci arrangements have been identified that
					reflect metabolic need or specialization. Comparison of the phylogenetic
					trees of core erythritol catabolic genes with species phylogeny provides
					evidence that is consistent with these loci having been horizontally
					transferred from the alpha-proteobacteria into both the beta and
					gamma-proteobacteria. ABC transporters within these loci adopt 2 unique
					genetic arrangements, and although biological data suggests they are
					functional erythritol transporters, phylogenetic analysis suggests they may
					not be orthologs and probably should be considered analogs. Finally,
					evidence for the presence of paralogs, and xenologs of erythritol catabolic
					genes in some of the genomes included in the analysis is provided.
Description
Keywords
Citation
BMC Microbiology. 2013 Feb 23;13(1):46