11家族（GH11）木聚糖酶是生产低聚木糖的重要水解酶，其催化形成特异性产物机制模糊不清导致低聚木糖工业生产效率低下，阻碍了健康产业发展。申请者前期研究发现GH11木聚糖酶非功能域N/C端Linker结构对水解产物形成影响显著。本项目拟以水解特性优良Streptomyces sp.源GH11木聚糖酶为模型，系统分析酶的进化及N/C端Linker结构多样性与水解特性的关系，探究该典型结构存在形式及序列组成对水解特性的影响；采用同源建模和晶体解析结合光谱学、分子动力学和量子力学综合分析该结构对酶底物结合域裂隙运动的自由度及与底物分子结合作用的趋向性变化；从酶分子环境偏好性（偏向性）角度综合分析该结构影响GH11木聚糖酶形成特异性产物分子机制。项目实施可为丰富水解酶类分子催化基础理论、获得特异性优良酶提供理论指导，为促进功能低聚糖高效生产、推进我国全面健康的发展战略具有重要的科学价值和实际意义。

Although the GH11 xylanase is the key hydrolytic enzyme in xylan-oligosaccharides production, the unclear catalytic characteristics lead to the low efficiency of xylan-oligosaccharides production and hinder the development of health industry. Our preliminary data found the non-functional domain N/C end Linker structure could significantly influence the hydrolytic characteristics of GH11 xylanase. Taking GH11 xylanase from Streptomyces sp. which shows the great hydrolytic characteristic as the model, the present proposal will systematically analyze the enzyme evolution and the interactions of N/C end Linker structure diversity with hydrolytic characteristics, and explore the effects of the certain typical structure and its sequence on enzyme hydrolytic characteristics; investigate the effects of the structure on degree of freedom of fracture movement in enzyme substrate binding domain and substrates binding tendency using homology modeling and crystal analysis combined with spectroscopy, molecular dynamics and quantum mechanics; comprehensively elucidate the molecular mechanism of N/C end Linker structure influenced the catalytic characteristics of GH11 xylanase from the standpoint of enzymatic environmental preference. Result of the study will provide theoretical guidance for the enrichment of the enzyme fundamental catalytic theory and the acquisition of well-specific enzymes, facilitate the high efficiency of oligosaccharides production, and advance the China comprehensive health development strategy.