Because CGCFinder predicted no CGC for this PUL, the gene cluster depicted below contains dbCAN2 and CGC signature predictions for all genes in the PUL, instead of a predicted CGC.




31198441, Biotechnol Biofuels. 2019 Jun 10;12:144. doi: 10.1186/s13068-019-1483-y. eCollection 2019.

Characterization method

recombinant protein expression,enzyme activity assay

Genomic accession number


Nucelotide position range







Ruminiclostridium cellulolyticum/1521

Degradation or Biosynthesis


Cluster number


Gene name

Gene position

Gene type

Found by CGCFinder?

- 1 - 1608 (+) CAZyme: GH43|GH43_16|CBM6 No
- 1714 - 3339 (+) CAZyme: GH10|CBM6 No
- 3407 - 4981 (+) CAZyme: GH43|GH43_29|CBM6 No
- 5004 - 6476 (+) CAZyme: CE1|CBM6 No
- 6552 - 8792 (+) CAZyme: GH43_10|CBM6 No
- 8876 - 10486 (+) CAZyme: GH62|CBM6 No
- 10561 - 12090 (+) CAZyme: GH43|GH43_29|CBM6 No
- 12179 - 15046 (+) CAZyme: GH146|CBM22 No
- 15155 - 16969 (+) CAZyme: GH27|CBM6 No
- 16999 - 20367 (+) CAZyme: GH59|CBM6 No
- 20431 - 23478 (+) CAZyme: GH2|CBM6 No
- 23539 - 25881 (+) CAZyme: GH62|CE6|CBM6 No
- 26098 - 29592 (+) CAZyme: CBM32|GH95|CBM6 No
- 29687 - 31576 (+) CAZyme: GH30_8|CBM6 No




31198441, Biotechnol Biofuels. 2019 Jun 10;12:144. doi: 10.1186/s13068-019-1483-y. eCollection 2019.


The xyl-doc gene cluster of Ruminiclostridium cellulolyticum encodes GH43- and GH62-alpha-l-arabinofuranosidases with complementary modes of action.


Mroueh M, Aruanno M, Borne R, de Philip P, Fierobe HP, Tardif C, Pages S


BACKGROUND: The alpha-l-arabinofuranosidases (alpha-l-ABFs) are exoenzymes involved in the hydrolysis of alpha-l-arabinosyl linkages in plant cell wall polysaccharides. They play a crucial role in the degradation of arabinoxylan and arabinan and they are used in many biotechnological applications. Analysis of the genome of R. cellulolyticum showed that putative cellulosomal alpha-l-ABFs are exclusively encoded by the xyl-doc gene cluster, a large 32-kb gene cluster. Indeed, among the 14 Xyl-Doc enzymes encoded by this gene cluster, 6 are predicted to be alpha-l-ABFs belonging to the CAZyme families GH43 and GH62. RESULTS: The biochemical characterization of these six Xyl-Doc enzymes revealed that four of them are alpha-l-ABFs. GH43(16)-1229 (RcAbf43A) which belongs to the subfamily 16 of the GH43, encoded by the gene at locus Ccel_1229, has a low specific activity on natural substrates and can cleave off arabinose decorations located at arabinoxylan chain extremities. GH43(10)-1233 (RcAbf43A(d2,3)), the product of the gene at locus Ccel_1233, belonging to subfamily 10 of the GH43, can convert the double arabinose decorations present on arabinoxylan into single O2- or O3-linked decorations with high velocity (k (cat) = 16.6 +/- 0.6 s(-1)). This enzyme acts in synergy with GH62-1234 (RcAbf62A(m2,3)), the product of the gene at locus Ccel_1234, a GH62 alpha-l-ABF which hydrolyzes alpha-(1 --> 3) or alpha-(1 --> 2)-arabinosyl linkages present on polysaccharides and arabinoxylooligosaccharides monodecorated. Finally, a bifunctional enzyme, GH62-CE6-1240 (RcAbf62B(m2,3)Axe6), encoded by the gene at locus Ccel_1240, which contains a GH62-alpha-l-ABF module and a carbohydrate esterase (CE6) module, catalyzes deacylation of plant cell wall polymers and cleavage of arabinosyl mono-substitutions. These enzymes are also active on arabinan, a component of the type I rhamnogalacturonan, showing their involvement in pectin degradation. CONCLUSION: Arabinofuranosyl decorations on arabinoxylan and pectin strongly inhibit the action of xylan-degrading enzymes and pectinases. alpha-l-ABFs encoded by the xyl-doc gene cluster of R. cellulolyticum can remove all the decorations present in the backbone of arabinoxylan and arabinan, act synergistically, and, thus, play a crucial role in the degradation of plant cell wall polysaccharides.