8yjj

Publication Abstract from PubMed

Endo-beta-1,4-xylanases degrade heteroxylans that constitute the lignocellulosic plant cell wall. This enzyme is widely used in the food, paper, textile, and biorefinery industries. Temperature affects the optimum activity of xylanase and is an important factor in its application. Various structural analyses of xylanase have been performed, but its structural influence by temperature is not fully elucidated. To better understand the structural influence of xylanase due to temperature, the crystal structure of xylanase II from Trichoderma longibrachiatum (TloXynII) at room and cryogenic temperatures was determined at 2.1 and 1.9 A resolution, respectively. The room-temperature structure of TloXynII (TloXynII(RT)) showed a B-factor value 2.09 times higher than that of the cryogenic-temperature structure of TloXynII (TloXynII(Cryo)). Subtle movement of the catalytic and substrate binding residues was observed between TloXynII(RT) and TloXynII(Cryo). In TloXynII(RT), the thumb domain exhibited high flexibility, whereas in TloXynII(Cryo), the finger domain exhibited high flexibility. The substrate binding cleft of TloXynII(RT) was narrower than that of TloXynII(Cryo), indicating a distinct finger domain conformation. Numerous water molecule networks were observed in the substrate binding cleft of TloXynII(Cryo), whereas only a few water molecules were observed in TloXynII(RT). These structural analyses expand our understanding of the temperature-dependent conformational changes in xylanase.

Temperature-dependent structural changes in xylanase II from Trichoderma longibrachiatum.,Nam KH Carbohydr Res. 2024 Jul;541:109173. doi: 10.1016/j.carres.2024.109173. Epub 2024 , May 31. PMID:38833820^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.