PUL ID

PUL0387

PubMed

20081036, J Bacteriol. 2010 Mar;192(6):1487-97. doi: 10.1128/JB.01418-09. Epub 2010 Jan 15.

Characterization method

gene deletion mutant and growth assay, qRT-PCR, GlcNAc phosphorylation assays

Genomic accession number

NC_003902.1

Nucelotide position range

4057997-4068416

Substrate

N-acetylglucosamine

Loci

XCC3408-XCC3414

Species

Xanthomonas campestris pv. campestris/340

Degradation or Biosynthesis

degradation

Cluster number

1

Gene name

Gene position

Gene type

Found by CGCFinder?

- 1 - 2574 (-) TC: gnl|TC-DB|Q9AAZ6|1.B.14.12.2 Yes
- 3345 - 4676 (-) other Yes
nagA 5030 - 6184 (-) CAZyme: CE9 Yes
- 6187 - 7215 (-) STP: STP|SIS,STP|SIS Yes
- 7222 - 8289 (-) TF: DBD-Pfam|LacI,DBD-SUPERFAMILY|0036955 Yes
- 8330 - 9607 (-) TC: gnl|TC-DB|A1S4V0|2.A.1.7.9 Yes
- 9653 - 10408 (-) TF: DBD-Pfam|GntR,DBD-SUPERFAMILY|0037767 No

PUL ID

PUL0387

PubMed

20081036, J Bacteriol. 2010 Mar;192(6):1487-97. doi: 10.1128/JB.01418-09. Epub 2010 Jan 15.

Title

Identification and regulation of the N-acetylglucosamine utilization pathway of the plant pathogenic bacterium Xanthomonas campestris pv. campestris.

Author

Boulanger A, Dejean G, Lautier M, Glories M, Zischek C, Arlat M, Lauber E

Abstract

Xanthomonas campestris pv. campestris, the causal agent of black rot disease of brassicas, is known for its ability to catabolize a wide range of plant compounds. This ability is correlated with the presence of specific carbohydrate utilization loci containing TonB-dependent transporters (CUT loci) devoted to scavenging specific carbohydrates. In this study, we demonstrate that there is an X. campestris pv. campestris CUT system involved in the import and catabolism of N-acetylglucosamine (GlcNAc). Expression of genes belonging to this GlcNAc CUT system is under the control of GlcNAc via the LacI family NagR and GntR family NagQ regulators. Analysis of the NagR and NagQ regulons confirmed that GlcNAc utilization involves NagA and NagB-II enzymes responsible for the conversion of GlcNAc-6-phosphate to fructose-6-phosphate. Mutants with mutations in the corresponding genes are sensitive to GlcNAc, as previously reported for Escherichia coli. This GlcNAc sensitivity and analysis of the NagQ and NagR regulons were used to dissect the X. campestris pv. campestris GlcNAc utilization pathway. This analysis revealed specific features, including the fact that uptake of GlcNAc through the inner membrane occurs via a major facilitator superfamily transporter and the fact that this amino sugar is phosphorylated by two proteins belonging to the glucokinase family, NagK-IIA and NagK-IIB. However, NagK-IIA seems to play a more important role in GlcNAc utilization than NagK-IIB under our experimental conditions. The X. campestris pv. campestris GlcNAc NagR regulon includes four genes encoding TonB-dependent active transporters (TBDTs). However, the results of transport experiments suggest that GlcNAc passively diffuses through the bacterial envelope, an observation that calls into question whether GlcNAc is a natural substrate for these TBDTs and consequently is the source of GlcNAc for this nonchitinolytic plant-associated bacterium.