Solution structure of a ubiquitin-like domain from tubulin-binding cofactor B
Solution structure of a ubiquitin-like domain from tubulin-binding cofactor B
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DOI：
10.1074/jbc.m409422200
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发表时间：
2004-11-05
影响因子：
4.8
通讯作者：
Volkman, BF
中科院分区：
文献类型：
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作者：
Lytle, BL;Peterson, FC;Volkman, BF
微管蛋白α-异源二聚体的正确折叠和组装涉及一组蛋白质辅因子A到E的介导的逐步过程。当微管蛋白单体从伴侣蛋白CCT中释放出来时，它们通过一组独特的蛋白质相互作用结构域被折叠途径中的每个辅因子作用。以前已经报道了辅因子A和辅因子B(Cob)的C端CAP-Gly结构域的三维结构。在这里，我们报告了秀丽隐杆线虫Cob N-末端结构域的核磁共振结构，并表明它与最近基于生物信息学分析(Grynberg，M.，Jaroszewski，L.和Godzik，A.(2003)BMC BioInformation 4，46)推测的泛素非常相似。COB与部分折叠的α-微管蛋白单体结合，通过序列和结构比较，确定了N-末端结构域中可能的微管蛋白结合基序。基于同源辅因子E泛素样结构域的建模，我们假设辅因子B和E可能通过它们的β-GRAP结构域以类似于PB1和caspase激活的脱氧核糖核酸酶超家族蛋白相互作用结构域的方式相互作用。
Proper folding and assembly of tubulin alphabeta-heterodimers involves a stepwise progression mediated by a group of protein cofactors A through E. Upon release of the tubulin monomers from the chaperonin CCT, they are acted upon by each cofactor in the folding pathway through a unique combination of protein interaction domains. Three-dimensional structures have previously been reported for cofactor A and the C-terminal CAP-Gly domain of cofactor B (CoB). Here we report the NMR structure of the N-terminal domain of Caenorhabditis elegans CoB and show that it closely resembles ubiquitin as was recently postulated on the basis of bioinformatic analysis (Grynberg, M., Jaroszewski, L., and Godzik, A. (2003) BMC Bioinformatics 4, 46). CoB binds partially folded alpha-tubulin monomers, and a putative tubulin-binding motif within the N-terminal domain is identified from sequence and structure comparisons. Based on modeling of the homologous cofactor E ubiquitin-like domain, we hypothesize that cofactors B and E may associate via their beta-grasp domains in a manner analogous to the PB1 and caspase-activated deoxyribonuclease superfamily of protein interaction domains.