Arabitol Metabolism of Corynebacterium glutamicum and Its Regulation by AtlR

Abstract

Expression profiling of Corynebacterium glutamicum in comparison to a derivative deficient in the transcriptional regulator AtlR (previously known as SucR or MtlR) revealed eight genes showing more than 4-fold higher mRNA levels in the mutant. Four of these genes are located in the direct vicinity of the atlR gene, i.e., xylB, rbtT, mtlD, and sixA, annotated as encoding xylulokinase, the ribitol transporter, mannitol 2-dehydrogenase, and phosphohistidine phosphatase, respectively. Transcriptional analysis indicated that atlR and the four genes are organized as atlR-xylB and rbtT-mtlD-sixA operons. Growth experiments with C. glutamicum and C. glutamicum ⌬atlR, ⌬xylB, ⌬rbtT, ⌬mtlD, and ⌬sixA derivatives with sugar alcohols revealed that (

Formation of xylitol and xylitol-5-phosphate and its impact on growth of d-xylose-utilizing Corynebacterium glutamicum strains

“…This finding is consistent with the fact that the ISO strain carries a plasmidborn overexpression of xylB and the resulting xylulokinase shows side activity in phosphorylating xylitol to xylitol-5-phosphate (Sasaki et al, 2010). Small amounts of xylitol-5-phosphate in the WMB and WT_P strain indicate that xylulokinase activity is comparably low in these strains, which might be due to the already described repression of xylB by D-glucose and absence of a suitable inducer such as D-arabitol (Laslo et al, 2012).…”

“…In the genome of C. glutamicum ATCC13032, the xylB gene is located in a gene cluster involved in ribitol, mannitol and arabitol metabolism and recently it was shown that Darabitol activates the transcriptional regulator AtlR of the D-arabitol operon leading to the expression of several genes (including xylB) that are essential for growth on D-arabitol (Laslo et al, 2012). To further study the growth inhibiting effect of xylitol, mediated through the expression of xylB and/ or ptsF, cultivation experiments with C. glutamicum WT_P, WMB and ISO were carried out on CGXII medium with either D-glucose, Darabitol or D-fructose as carbon source, and additional supplements of 10 mM and 100 mM xylitol, respectively (Table 2).…”

“…Plasmids pEKEx3 Spec R ; C. glutamicum/ E. coli shuttle vector for regulated gene expression; (Ptac, lacI Q , pBL1 oriVCg, pUC18 oriVEc) (Hoffelder et al, 2010) pVWEx3-xylAXc-xylBCg Spec R ; pEKEx3 derivative for the regulated expression of xylAXc of X. campestris and xylBCg of C. glutamicum (Meiswinkel et al, 2013) pVWEx3-xylXABCDCc Spec R ; pEKEx3 derivative for the regulated expression of xylXABCDCc of C. crescentus (Radek et al, 2014) pK19mobsacB Kan r ; vector for allelic exchange in C. glutamicum (pK18 oriVEc sacB lacZα) (Schäfer et al, 1994) pK19mobsacB∆ptsF Kan r , pK19mobsacB derivative for in-frame deletion of ptsF this study pK19mobsacB∆xylB Kan r , pK19mobsacB derivative for in-frame deletion of xylB (Laslo et al, 2012) …”

Transport and Catabolism of Pentitols by Listeria monocytogenes

“…Bacteria from most phyla, such as the proteobacteria Klebsiella pneumoniae [Heuel et al, 1997] and Pseudomonas fluorescens [Brün ker et al, 1998], the actinobacterium Corynebacterium glutamicum [Laslo et al, 2012], and the firmicutes Enterococcus avium [Povelainen et al, 2003] and Listeria monocytogenes [Saklani-Jusforgues et al, 2001] utilize D -arabitol as a carbon and energy source. The γ-proteobacterium K. pneumoniae and the actinobacterium C. glutamicum take up D -arabitol via closely related transporters of the major facilitator superfamily (DalT and RbtT, respectively).…”

C 1 Metabolism in Corynebacterium glutamicum: an Endogenous Pathway for Oxidation of Methanol to Carbon Dioxide

“…RamA and RamB are global transcriptional regulators in C. glutamicum and control genes for enzymes of the central metabolism (26,56,57). SucR is now termed AtlR (58). In the case of ald, RamA was described as an essential activator and RamB as a weak repressor (44).…”