Experimental evidence of a xylose-catabolic pathway on the pAO1 megaplasmid of Arthrobacter nicotinovorans

• Main Authors: Marius Mihasan, Marius Stefan, Vlad Artenie
• Format: Article
• Language: English
• Published: "Alexandru Ioan Cuza" University of Iași 2012-09-01
• Series: Analele Ştiinţifice Ale Universităţii Alexandru Ioan Cuza din Iași,Sectiunea II A : Genetica si Biologie Moleculara
• Subjects: Arthrobacter; xylose; pAO1
• Online Access: http://www.gbm.bio.uaic.ro/index.php/gbm/article/view/264

The pAO1 megaplasmid of A. nicotinovorans consists of 165 ORF's related mainly to nicotine degradation, uptake and utilization of carbohydrates, amino acids and sarcosine. A putative sugar catabolic pathway consisting of 11 ORF's organized as a single operon were previously described. The current work brings experimental data supporting the existence of a D-Xylose catabolic pathway on the pAO1 megaplasmid. When grown on D-xylose containing media, the cells harboring the pAO1 megaplasmid grow to higher cell densities and also express the OxRe protein coded by the megaplasmid. A putative pathway similar to Weimberg pentose pathway is postulated, in which D-xylose is transported in the cell by the ABC-type transport system and then transformed using the putative sugar-dehidrogenase OxRe to D-xylonate, which is further degrated to 2-ketoglutarate and integrated into the general metabolism of the cell