PUL ID

PUL0209

PubMed

17644603, J Bacteriol. 2007 Oct;189(19):7053-61. doi: 10.1128/JB.00845-07. Epub 2007 Jul 20.

Characterization method

enzyme activity assay, gene deletion mutant and growth assay

Genomic accession number

CP002038.1

Nucelotide position range

3416624-3428226

Substrate

galactan

Loci

ganR-ganK

Species

Dickeya dadantii/204038

Degradation or Biosynthesis

degradation

Cluster number

1

Gene name

Gene position

Gene type

Found by CGCFinder?

ganR 1 - 1074 (-) TF: DBD-Pfam|LacI,DBD-SUPERFAMILY|0036955 No
ganL 1342 - 2613 (+) TC: gnl|TC-DB|P02943|1.B.3.1.1 Yes
ganB 3202 - 5259 (-) CAZyme: GH42 Yes
ganA 5396 - 6595 (-) CAZyme: GH53 Yes
ganG 6601 - 7497 (-) TC: gnl|TC-DB|O07011|3.A.1.1.2 Yes
ganF 7508 - 8815 (-) TC: gnl|TC-DB|O32261|3.A.1.1.2 Yes
ganE 8889 - 10136 (-) TC: gnl|TC-DB|O07009|3.A.1.1.2 Yes
ganK 10494 - 11603 (+) TC: gnl|TC-DB|Q01937|3.A.1.1.4 Yes
- 11569 - 11603 (-) CDS No

PUL ID

PUL0209

PubMed

17644603, J Bacteriol. 2007 Oct;189(19):7053-61. doi: 10.1128/JB.00845-07. Epub 2007 Jul 20.

Title

Characterization of the Erwinia chrysanthemi Gan locus, involved in galactan catabolism.

Author

Delangle A, Prouvost AF, Cogez V, Bohin JP, Lacroix JM, Cotte-Pattat NH

Abstract

beta-1,4-Galactan is a major component of the ramified regions of pectin. Analysis of the genome of the plant pathogenic bacteria Erwinia chrysanthemi revealed the presence of a cluster of eight genes encoding proteins potentially involved in galactan utilization. The predicted transport system would comprise a specific porin GanL and an ABC transporter made of four proteins, GanFGK(2). Degradation of galactans would be catalyzed by the periplasmic 1,4-beta-endogalactanase GanA, which released oligogalactans from trimer to hexamer. After their transport through the inner membrane, oligogalactans would be degraded into galactose by the cytoplasmic 1,4-beta-exogalactanase GanB. Mutants affected for the porin or endogalactanase were unable to grow on galactans, but they grew on galactose and on a mixture of galactotriose, galactotetraose, galactopentaose, and galactohexaose. Mutants affected for the periplasmic galactan binding protein, the transporter ATPase, or the exogalactanase were only able to grow on galactose. Thus, the phenotypes of these mutants confirmed the functionality of the gan locus in transport and catabolism of galactans. These mutations did not affect the virulence of E. chrysanthemi on chicory leaves, potato tubers, or Saintpaulia ionantha, suggesting an accessory role of galactan utilization in the bacterial pathogeny.