褐色高温单胞菌编码内切纤维素酶 E4 的催化域(CAD) DNA 片段与丙酮丁醇梭菌编码对接蛋白的基因片段通过装配 PCR 方法，在大肠杆菌 BL21(DE3)重组表达形成融合蛋白 E4SD，然后在钙离子介导下与在大肠杆菌 BL21(DE3)表达的来源于丙酮丁醇梭菌的含有纤维素结合单元和 2 个粘连蛋白的脚手架蛋白 CipA 互相作用，在体外组装成微纤维小体．结果显示，E4SD 通过 C- 端的对接蛋白成功地与脚手架蛋白上的粘连蛋白互相作用，结合到脚手架蛋白上，且 E4SD 在微纤维小体中的羧甲基纤维素和微晶纤维素酶活性分别提高到游离状态下的 130% 与 300%，提示非纤维小体酶系的纤维素酶，特别是远缘物种的具有优良酶特性的纤维素酶可以通过将其与脚手架蛋白同样种属的对接蛋白添加至末端，从而参与到丙酮丁醇梭菌的纤维小体中来，并与其他纤维素酶在脚手架蛋白的参与下协调作用，高效降解纤维素．

Discussed in this paper are the heterologous expression of a truncated scaffolding protein from Clostri-dium acetobutylicum containing a cellulose- binding module and two cohesin modules,and a recombinant endoglu-canase E4SD,a family of 9 cellulase Cel9A catalysis domain from Thermomonospora fusca appended with C.aceto-butylicum dockerin in C- terminal,which are both produced by E.coli BL21 (DE3),and subsequently purified,mixed,and then assembled with minicellulosomes by calcium- mediated cohesin- dockerin interaction ex- vivo.Theresults show that the truncated scaffoldin CipA is successfully assembled with recombinant endoglucanase E4SD toform minicellulosome via cohesin- dockerin interaction,and that,as compared with those in enzyme- free state,theenzyme activities of E4SD in carboxymethyl cellulose hydrolysis and microcrystal cellulose hydrolysis respectivelyimprove by 30% and 200%.Thus,it is demonstrated that noncellulosomal cellulase,especially the cellulase withexcellent enzymatic characteristics from other species,can incorporate into C.acetobutylicum cellulosome by ap-pending a C.acetobutylicum dockerin and can synergize with other cellulase to hydrolyze cellulose more efficiently.