Proteins

A protein. The present invention relates to a modified GH10 xylanase or a fragment thereof having xylanase activity, wherein the modified GH10 xylanase or fragment thereof has increased thermostability compared to a parent GH10 xylanase, which parent GH10 xylanase has been modified at least two of the following positions: 7. 33, 79, 217 and 298, wherein the numbering is based on the amino acid numbering of FveXyn4 (SEQ ID No. 1). In particular, the modified xylanase according to the invention has the following modifications: N7D; T33V; K79Y, K79V, K79F, K79I, K L or K79M (preferably K79Y, K79F or K79V, more preferably K79Y); a217Q, A217E, A217P, A D or a217M (preferably a217Q, A217E or a217P, more preferably a 217Q); and T298Y, T F or T298W (preferably T298Y or T298F, more preferably T298Y).