Novel modular endo-β-1,4-xylanase with transglycosylation activity from Cellulosimicrobium sp. strain HY-13 that is homologous to inverting GH family 6 enzymes

► The novel, modular β-1,4-xylanase gene (xylK2) of Cellulosimicrobium sp. strain HY-13 was cloned. ► XylK2 was a retaining enzyme with an N-terminal catalytic GH6-like domain. ► XylK2ΔFn3-CBM 2 displayed high transferase activity toward p-nitrophenylcellobioside. ► Birchwood xylan was degraded by XylK2ΔFn3-CBM 2 to xylobiose (59.2%) and xylotriose (40.8%). ► The enzyme activity increased by 2.0-fold in the presence of 50 mM xylobiose.