A novel family of hemicellulolytic alpha-glucuronidase.
Investigation of the xylanolytic enzyme system of the xylose-fermenting yeast Pichia stipitis resulted in the discovery of an extracellular alpha-glucuronidase efficiently debranching hardwood glucuronoxylan. This activity is not exhibited by more extensively investigated alpha-glucuronidases of glycoside hydrolase (GH) family 67, operating on substrates in which the uronic acid is linked to the non-reducing xylopyranosyl residues of main chain fragments. The N-terminus of the purified enzyme corresponded exactly to the P. stipitis gene ABN67901 coding for a protein of unknown function. BLAST search revealed the presence of similar genes in genomes of other microorganisms. These results lead to the emergence of a new family of alpha-glucuronidases.
Ryabova
Olena
O
Institute of Chemistry, Slovak Academy of Sciences, Department of Carbohydrate Enzymology, Dúbravská cesta 9, 845 38 Bratislava 45, Slovakia.
Vrsanská
Mária
M
Kaneko
Satoshi
S
van Zyl
Willem H
WH
Biely
Peter
P