Cohesin‐Dockerin Interactions and Folding
Cohesin‐Dockerin Interactions and Folding
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Cohesin-Dockerin 交互和折叠
DOI：
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
K. Sakka
中科院分区：
文献类型：
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作者：
J. Wu;M. Newcomb;K. Sakka
进行了许多研究来表征黏结蛋白-码头蛋白的相互作用。这些研究包括测量黏结蛋白-dockerin的亲和力，通过位点定向诱变鉴定关键氨基酸残基，以及确定dockerin、黏结蛋白及其复合物的分子结构。内聚蛋白在同一支架蛋白内具有高度保守性，序列同源性高于50%。热胞梭菌CipA支架蛋白内聚蛋白与纤维素体催化组分dockerin的相互作用可归类为I型，CipA dockerin与其对应物dockerin的相互作用可归类为II型。I型黏结蛋白和连接蛋白包括那些来自不同微生物的模块。然而，这种分类是基于序列同源性的，并不一定意味着相同类型的模块之间的识别。事实上，用C. thermocellum和Clostridium celluulolyticum的内聚蛋白和dockerin分别证明了种间特异性。在这项工作中，Pages等人发现C. thermocellum Cel48A（即CelS）及其dockerin不能识别C. cellulose olyticum支架蛋白CipC的内聚蛋白1。黏结蛋白和dockerin之间极高的亲和力以及它们在纤维素组装中的重要作用促使人们对确定它们的分子结构以阐明黏结蛋白-dockerin识别的分子机制产生了兴趣。利用C. thermocellum Xyn10B的dockerin晶体和CipA的cohesin2晶体，在大肠杆菌中共表达并纯化成复合物，获得了适合x射线分析的良好晶体，在x射线晶体学上取得了第一次成功。
Many investigations were conducted to characterize the cohesin-dockerin interactions. These studies include measuring cohesin-dockerin affinity, identifying critical amino acid residues by site-directed mutagenesis, and determining the molecular structures of the dockerin, cohesin, and its complex. Cohesins are highly conserved within the same scaffolding protein, with sequence identities higher than 50%. The interactions between the cohesin of the Clostridium thermocellum CipA scaffolding protein and the dockerin of cellulosomal catalytic components are categorized as type I, and the interactions between the dockerin of CipA and its counterpart are categorized as type II. The type I cohesins and dockerins include those modules from different microorganisms. This classification, however, is based on sequence homology and does not necessarily imply recognition among the same type of modules. Indeed, interspecies specificity was demonstrated using cohesins and dockerins from C. thermocellum and Clostridium cellulolyticum, respectively. In this work, Pages et al. found that C. thermocellum Cel48A (i.e., CelS), with its dockerin, did not recognize cohesin 1 of the C. cellulolyticum scaffolding protein CipC. The extremely high affinity between cohesin and dockerin and their important roles in cellulosome assembly have prompted interest in determining their molecular structures to elucidate the molecular mechanism of the cohesin-dockerin recognition. The first success in X-ray crystallography of a cohesin-dockerin complex was brought about by using a crystal of the dockerin of C. thermocellum Xyn10B and cohesin 2 of CipA, coexpressed in Escherichia coli and purified as a complex, yielding a good crystal suitable for X-ray analysis.
影响因子：
3.9
作者：
Lytle, BL;Volkman, BF;Wu, JHD
通讯作者：
Wu, JHD