泛肽-核糖体蛋白S27a(Ubiquitin-ribosomal protein S27a,UBRS27a)是泛肽和核糖体蛋白的融合蛋白,N端为泛肽,C端由含C2-C2型锌指结构域的高度保守核糖体蛋白S27a构成。在真核细胞中表达时,被酶解成泛肽和核糖体蛋白。该多功能核糖体蛋...泛肽-核糖体蛋白S27a(Ubiquitin-ribosomal protein S27a,UBRS27a)是泛肽和核糖体蛋白的融合蛋白,N端为泛肽,C端由含C2-C2型锌指结构域的高度保守核糖体蛋白S27a构成。在真核细胞中表达时,被酶解成泛肽和核糖体蛋白。该多功能核糖体蛋白在各种活性增殖细胞和瘤组织中高度表达,在多种类型的肿瘤细胞中,该基因的过量表达是一个典型特征。本实验室对该蛋白在家蚕中的作了初步研究,也发现RPS27a在活性增殖细胞中表达量很高。大多数核糖体蛋白的功能还没有完全探明,它们不仅仅在组装成核糖体时起作用,往往还有核糖体外的功能。回顾了最近几年有关该融合蛋白以及与它相关的泛肽途径、核糖体蛋白与肿瘤之间的关系。通过对它们的研究,有可能预示肿瘤的发生和发展,并为肿瘤临床诊断提供依据,为恶性肿瘤的治疗提供靶点。展开更多
从小麦条锈菌吸器cDNA文库中鉴定到一个泛肽-核糖体蛋白S27a(Ubiquitin-ribosomal protein S27a,UBRS27a)基因,命名为PsUBRS27a。该基因开放阅读框为480bp,编码包含159个氨基酸残基的蛋白质,其氨基酸序列含有典型的UBRS27a蛋白所具有的u...从小麦条锈菌吸器cDNA文库中鉴定到一个泛肽-核糖体蛋白S27a(Ubiquitin-ribosomal protein S27a,UBRS27a)基因,命名为PsUBRS27a。该基因开放阅读框为480bp,编码包含159个氨基酸残基的蛋白质,其氨基酸序列含有典型的UBRS27a蛋白所具有的ubiquitin和Ribosomal_S27结构域;序列比对发现UBRS27a蛋白在不同物种中高度保守,但PsUBRS27a蛋白在进化上与柄锈菌属的UBRS27a蛋白亲缘关系最近;种内多态性分析发现PsUBRS27a基因在不同小麦条锈菌菌系中的序列非常保守,无核苷酸变化;实时荧光定量PCR结果表明,PsUBRS27a基因在条锈菌侵染小麦过程中呈上调表达趋势,高峰期为接种后168h。展开更多
Using differential screening of a leaf cDNA library prepared from a bean cultivar ( Phaseolus vulgaris L. cv. Saxa) exposed to HgCl 2, the authors have isolated and characterized two heavy metal_regulated cDNA fra...Using differential screening of a leaf cDNA library prepared from a bean cultivar ( Phaseolus vulgaris L. cv. Saxa) exposed to HgCl 2, the authors have isolated and characterized two heavy metal_regulated cDNA fragments, designated as PvSR 5 and PvSR 51 ( Phaseolus vulgaris stress_related gene). The sequences of the cDNA inserts and homological analysis showed that both PvSR 5 and PvSR 51 encode a polyubiquitin respectively. The polyubiquitin genes were constitutively expressed in roots but weakly expressed in stems and leaves. Northern blot analysis revealed a low level of transcripts of polyubiquitin in unstressed bean leaves, but the gene expression was strongly stimulated by heavy metals, elevated temperature and salicylic acid, whereas wounding had almost no effect. These suggested that polyubiquitin might play important roles in resistance to heavy metals and various environmental stresses.展开更多
We describe an implementation of the cluster-in-molecule （CIM） resolution of the identity （RI） approximation second-order Moller-Plesset perturbation theory （CIM-RI-MP2）, with the purpose of extending RI-MP2 cal...We describe an implementation of the cluster-in-molecule （CIM） resolution of the identity （RI） approximation second-order Moller-Plesset perturbation theory （CIM-RI-MP2）, with the purpose of extending RI-MP2 calculations to very large systems. For typical conformers of several large polypeptides, we calculated their conformational energy differences with the CIM-RI-MP2 and the generalized energy-based fragmentation MP2 （GEBF-MP2） methods, and compared these results with the density functional theory （DFT） results obtained with several popular functionals. Our calculations show that the conformational energy differences obtained with CIM-RI-MP2 and GEBF-MP2 are very close to each other. In comparison with the GEBF-MP2 and CIM-RI-MP2 relative energies, we found that the DFT functionals （CAM-B3LYP-D3, LC-ωPBE-D3, M05-2X, M06-2X and coB97XD） can give quite accurate conformational energy differences for structurally similar conformers, but provide less-accurate results for structurally very different conformers.展开更多
文摘泛肽-核糖体蛋白S27a(Ubiquitin-ribosomal protein S27a,UBRS27a)是泛肽和核糖体蛋白的融合蛋白,N端为泛肽,C端由含C2-C2型锌指结构域的高度保守核糖体蛋白S27a构成。在真核细胞中表达时,被酶解成泛肽和核糖体蛋白。该多功能核糖体蛋白在各种活性增殖细胞和瘤组织中高度表达,在多种类型的肿瘤细胞中,该基因的过量表达是一个典型特征。本实验室对该蛋白在家蚕中的作了初步研究,也发现RPS27a在活性增殖细胞中表达量很高。大多数核糖体蛋白的功能还没有完全探明,它们不仅仅在组装成核糖体时起作用,往往还有核糖体外的功能。回顾了最近几年有关该融合蛋白以及与它相关的泛肽途径、核糖体蛋白与肿瘤之间的关系。通过对它们的研究,有可能预示肿瘤的发生和发展,并为肿瘤临床诊断提供依据,为恶性肿瘤的治疗提供靶点。
文摘从小麦条锈菌吸器cDNA文库中鉴定到一个泛肽-核糖体蛋白S27a(Ubiquitin-ribosomal protein S27a,UBRS27a)基因,命名为PsUBRS27a。该基因开放阅读框为480bp,编码包含159个氨基酸残基的蛋白质,其氨基酸序列含有典型的UBRS27a蛋白所具有的ubiquitin和Ribosomal_S27结构域;序列比对发现UBRS27a蛋白在不同物种中高度保守,但PsUBRS27a蛋白在进化上与柄锈菌属的UBRS27a蛋白亲缘关系最近;种内多态性分析发现PsUBRS27a基因在不同小麦条锈菌菌系中的序列非常保守,无核苷酸变化;实时荧光定量PCR结果表明,PsUBRS27a基因在条锈菌侵染小麦过程中呈上调表达趋势,高峰期为接种后168h。
文摘Using differential screening of a leaf cDNA library prepared from a bean cultivar ( Phaseolus vulgaris L. cv. Saxa) exposed to HgCl 2, the authors have isolated and characterized two heavy metal_regulated cDNA fragments, designated as PvSR 5 and PvSR 51 ( Phaseolus vulgaris stress_related gene). The sequences of the cDNA inserts and homological analysis showed that both PvSR 5 and PvSR 51 encode a polyubiquitin respectively. The polyubiquitin genes were constitutively expressed in roots but weakly expressed in stems and leaves. Northern blot analysis revealed a low level of transcripts of polyubiquitin in unstressed bean leaves, but the gene expression was strongly stimulated by heavy metals, elevated temperature and salicylic acid, whereas wounding had almost no effect. These suggested that polyubiquitin might play important roles in resistance to heavy metals and various environmental stresses.
基金supported by the National Natural Science Foundation of China(21073086,21333004)the National Basic Research Program of China(2011CB808501)
文摘We describe an implementation of the cluster-in-molecule （CIM） resolution of the identity （RI） approximation second-order Moller-Plesset perturbation theory （CIM-RI-MP2）, with the purpose of extending RI-MP2 calculations to very large systems. For typical conformers of several large polypeptides, we calculated their conformational energy differences with the CIM-RI-MP2 and the generalized energy-based fragmentation MP2 （GEBF-MP2） methods, and compared these results with the density functional theory （DFT） results obtained with several popular functionals. Our calculations show that the conformational energy differences obtained with CIM-RI-MP2 and GEBF-MP2 are very close to each other. In comparison with the GEBF-MP2 and CIM-RI-MP2 relative energies, we found that the DFT functionals （CAM-B3LYP-D3, LC-ωPBE-D3, M05-2X, M06-2X and coB97XD） can give quite accurate conformational energy differences for structurally similar conformers, but provide less-accurate results for structurally very different conformers.
