A C-Terminal Proline-Rich Sequence Simultaneously Broadens the Optimal Temperature and pH Ranges and Improves the Catalytic Efficiency of Glycosyl Hydrolase Family 10 Ruminal Xylanases

	A C-Terminal Proline-Rich Sequence Simultaneously Broadens the Optimal Temperature and pH Ranges and Improves the Catalytic Efficiency of Glycosyl Hydrolase Family 10 Ruminal Xylanases
	Li, Zhongyuan 1,2; Xue, Xianli 1; Zhao, Heng 1; Yang, Peilong 1; Luo, Huiying 1; Zhao, Junqi 3; Huang, Huoqing 1; Yao, Bin 1
刊名	APPLIED AND ENVIRONMENTAL MICROBIOLOGY
	2014-06-01
卷号	80 期号:11 页码:3426-3432
英文摘要	Efficient degradation of plant polysaccharides in rumen requires xylanolytic enzymes with a high catalytic capacity. In this study, a full-length xylanase gene (xynA) was retrieved from the sheep rumen. The deduced XynA sequence contains a putative signal peptide, a catalytic motif of glycoside hydrolase family 10 (GH10), and an extra C-terminal proline-rich sequence without a homolog. To determine its function, both mature XynA and its C terminus-truncated mutant, XynA-Tr, were expressed in Escherichia coli. The C-terminal oligopeptide had significant effects on the function and structure of XynA. Compared with XynA-Tr, XynA exhibited improved specific activity (12-fold) and catalytic efficiency (14-fold), a higher temperature optimum (50 degrees C versus 45 degrees C), and broader ranges of temperature and pH optima (pH 5.0 to 7.5 and 40 to 60 degrees C versus pH 5.5 to 6.5 and 40 to 50 degrees C). Moreover, XynA released more xylose than XynA-Tr when using beech wood xylan and wheat arabinoxylan as the substrate. The underlying mechanisms responsible for these changes were analyzed by substrate binding assay, circular dichroism (CD) spectroscopy, isothermal titration calorimetry (ITC), and xylooligosaccharide hydrolysis. XynA had no ability to bind to any of the tested soluble and insoluble polysaccharides. However, it contained more alpha helices and had a greater affinity and catalytic efficiency toward xylooligosaccharides, which benefited complete substrate degradation. Similar results were obtained when the C-terminal sequence was fused to another GH10 xylanase from sheep rumen. This study reveals an engineering strategy to improve the catalytic performance of enzymes.
WOS标题词	Science & Technology ; Life Sciences & Biomedicine
类目[WOS]	Biotechnology & Applied Microbiology ; Microbiology
研究领域[WOS]	Biotechnology & Applied Microbiology ; Microbiology
关键词[WOS]	TRICHODERMA-REESEI ; THERMAL-STABILITY ; ACTIVE-SITE ; BINDING ; ENDO-1,4-BETA-XYLANASE-II ; CELLULASES ; RUMEN
收录类别	SCI
语种	英语
WOS记录号	WOS:000336035200017
内容类型	期刊论文
源URL	[http://124.16.173.210/handle/834782/1364]
专题	天津工业生物技术研究所_酶工程实验室马延和 _期刊论文
作者单位	1.Chinese Acad Agr Sci, Feed Res Inst, Minist Agr, Key Lab Feed Biotechnol, Beijing 100193, Peoples R China 2.Tianjin Univ Sci & Technol, Key Lab Ind Fermentat Microbiol, Tianjin, Peoples R China 3.Chinese Acad Sci, Tianjin Inst Ind Biotechnol, Natl Engn Lab Ind Enzymes, Tianjin, Peoples R China
推荐引用方式 GB/T 7714	Li, Zhongyuan,Xue, Xianli,Zhao, Heng,et al. A C-Terminal Proline-Rich Sequence Simultaneously Broadens the Optimal Temperature and pH Ranges and Improves the Catalytic Efficiency of Glycosyl Hydrolase Family 10 Ruminal Xylanases[J]. APPLIED AND ENVIRONMENTAL MICROBIOLOGY,2014,80(11):3426-3432.
APA	Li, Zhongyuan.,Xue, Xianli.,Zhao, Heng.,Yang, Peilong.,Luo, Huiying.,...&Yao, Bin.(2014).A C-Terminal Proline-Rich Sequence Simultaneously Broadens the Optimal Temperature and pH Ranges and Improves the Catalytic Efficiency of Glycosyl Hydrolase Family 10 Ruminal Xylanases.APPLIED AND ENVIRONMENTAL MICROBIOLOGY,80(11),3426-3432.
MLA	Li, Zhongyuan,et al."A C-Terminal Proline-Rich Sequence Simultaneously Broadens the Optimal Temperature and pH Ranges and Improves the Catalytic Efficiency of Glycosyl Hydrolase Family 10 Ruminal Xylanases".APPLIED AND ENVIRONMENTAL MICROBIOLOGY 80.11(2014):3426-3432.