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

Table 4 Activities of the Xyl-Doc α-l-ABFs on AXOS

	A³X^a	A²XX^a	XA³XX^a	A²⁺³XX^a	XA²⁺³XX^a
GH43₁₆-1229	NA	NA	NA	NA	NA
GH43₁₀-1233	NA	NA	NA	A³XX/A²XX^b	XA²XX/XA³XX^b
GH62-1234	Araf/X2^b 0.0510 ± 0.0028^c	Araf/X3^b 0.590 ± 0.043^c	Araf/X4^b 0.116 ± 0.005^c	NA	NA
GH62-CE6-1240	Araf/X2^b 0.0300 ± 0.0005^c	Araf/X3^b 0.360 ± 0.028^c	Araf/X4^b 0.088 ± 0.0007^c	NA	NA

NA not active
^aSubstrates listed according to the nomenclature established by Fauré et al. [32] are written as follow: X2: xylobiose, X3:xylotriose, X4: xylotetraose
A³X: α-l-Araf-(1 → 3)-β-d-Xylp-(1 → 4)-d-Xylp
A²XX: α-l-Araf-(1 → 2)-β-d-Xylp-(1 → 4)-β-d-Xylp-(1 → 4)-d-Xylp
XA³XX: β-d-Xylp-(1 → 4)-[α-l-Araf-(1 → 3)]-β-d-Xylp-(1 → 4)-β-d-Xylp-(1 → 4)-d-Xylp
A²⁺³XX: [α-l-Araf-(1 → 2)][α-l-Araf-(1 → 3)]-β-d-Xylp-(1 → 4)-β-d-Xylp-(1 → 4)-d-Xylp
XA²⁺³XX: β-d-Xylp-(1 → 4)-[α-l-Araf-(1 → 2)][α-l-Araf-(1 → 3)]-β-d-Xylp-(1 → 4)-β-d-Xylp-(1 → 4)-d-Xylp
^bProducts of hydrolysis analyzed by HPAEC-PAD. The data show the mean and standard deviation of six independent experiments
^cSpecific activity in IU/µmol

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