贵州农业科学
貴州農業科學
귀주농업과학
GUIZHOU AGRICULTURAL SCIENCES
2015年
5期
138-145
,共8页
镰刀菌%植物细胞壁降解酶%结构
鐮刀菌%植物細胞壁降解酶%結構
렴도균%식물세포벽강해매%결구
Fusarium%plant cell wall degrading enzymes%structure
为探究植物细胞壁降解酶高效降解细胞壁的机制，用 RT-PCR 方法对 Q7-31T 菌株植物细胞壁降解酶基因片段进行克隆，使用 Prot-Param、SOPMA、ProtScale Server 等软件对质谱鉴定结果进行生物学分析。结果表明：将 Q7-31T 菌株植物细胞壁降解相关酶归为 GH5家族内切葡聚糖酶、GH7家族内切葡聚糖酶、GH7家族外切葡聚糖酶和 GH10家族内切木聚糖酶4类酶。这些相关酶类为中等分子量大小，二级结构由α-螺旋、延伸链、β-转角和无规则卷曲4种元件构成，其中无规则卷曲的数量最高；均为亲水性酶，磷酸化位点比例较高，存在1～2个糖基化位点；均存在较高比例的催化结构域，三级结构呈中空的 C 字形。结论：少量的糖基化位点、高比例的催化结构域、多变的三维构象、大量的磷酸化位点与高效的协同作用方式可能决定 Q7-31T 菌株的植物细胞壁降解酶对细胞壁的高效降解。
為探究植物細胞壁降解酶高效降解細胞壁的機製，用 RT-PCR 方法對 Q7-31T 菌株植物細胞壁降解酶基因片段進行剋隆，使用 Prot-Param、SOPMA、ProtScale Server 等軟件對質譜鑒定結果進行生物學分析。結果錶明：將 Q7-31T 菌株植物細胞壁降解相關酶歸為 GH5傢族內切葡聚糖酶、GH7傢族內切葡聚糖酶、GH7傢族外切葡聚糖酶和 GH10傢族內切木聚糖酶4類酶。這些相關酶類為中等分子量大小，二級結構由α-螺鏇、延伸鏈、β-轉角和無規則捲麯4種元件構成，其中無規則捲麯的數量最高；均為親水性酶，燐痠化位點比例較高，存在1～2箇糖基化位點；均存在較高比例的催化結構域，三級結構呈中空的 C 字形。結論：少量的糖基化位點、高比例的催化結構域、多變的三維構象、大量的燐痠化位點與高效的協同作用方式可能決定 Q7-31T 菌株的植物細胞壁降解酶對細胞壁的高效降解。
위탐구식물세포벽강해매고효강해세포벽적궤제，용 RT-PCR 방법대 Q7-31T 균주식물세포벽강해매기인편단진행극륭，사용 Prot-Param、SOPMA、ProtScale Server 등연건대질보감정결과진행생물학분석。결과표명：장 Q7-31T 균주식물세포벽강해상관매귀위 GH5가족내절포취당매、GH7가족내절포취당매、GH7가족외절포취당매화 GH10가족내절목취당매4류매。저사상관매류위중등분자량대소，이급결구유α-라선、연신련、β-전각화무규칙권곡4충원건구성，기중무규칙권곡적수량최고；균위친수성매，린산화위점비례교고，존재1～2개당기화위점；균존재교고비례적최화결구역，삼급결구정중공적 C 자형。결론：소량적당기화위점、고비례적최화결구역、다변적삼유구상、대량적린산화위점여고효적협동작용방식가능결정 Q7-31T 균주적식물세포벽강해매대세포벽적고효강해。
For exploring the mechanism of high-efficiency plant cell wall degradation process based on plant cell wall degrading enzymes from Fusarium strain Q7-31T,for the gene cloning and biological analysis,the methods respectively were PCR amplification and some bioinformatic softwares such as Prot-Param,SOPMA and ProtScale Server.Results:The plant cell wall degrading enzymes in Q7-31T are classified as:GH5 family endoglucanase,GH7 family endoglucanase,GH7 family exo-glucanase and GH10 family endoxylanase,which are consistent with mass spectrometry.The enzymes are medium molecular size,and the secondary structure consists of four elements:α-helix,extended strand,β-turn and random coil,of which random coil is most abundant;four enzyme classes are hydrophilic enzymes,and have higher proportion of phosphorylation sites.There are 1 ~ 2 glycosylation sites.Four enzymes are present in a higher proportion of catalytic domains and the tertiary structure of a hollow “C”shape. Conclusion:A small number of glycosylation sites,high proportion of catalytic domains,changeable three-dimensional conformations,large number of phosphorylation sites and high-efficiency synergism probably determine the high-efficiency degradation of plant cell wall degrading enzymes in strain Q7-31T.
