共查询到20条相似文献，搜索用时 15 毫秒
1.
AT-hook是一类新的DNA结合蛋白基序,与其他功能已知的DNA结合基序不同,AT-hook基序具有以精氨酸-甘氨酸-精氨酸-脯氨酸（RGRP）四个残基为中心的特征结构。AT-hook蛋白与DNA的特异结合是通过AT-hook基序的氨基酸残基与双链DNA小沟中富含AT碱基的区域相互作用完成的。AT-hook基序广泛存在于不同物种的DNA结合蛋白中,AT-hook蛋白在染色质结构组装和对目标基因转录活性的调控中起着重要的作用,进而影响生物的生长发育。 相似文献
2.
CpG—DNA特征结构与其免疫刺激特性的关系 总被引：1，自引：0，他引：1
CpG-DNA是一些具有免疫激活功能的以未甲基化的CpG基序为核心的DNA序列,它包括含CpG基序的人工合成的寡聚脱氧核苷酸(oligodeoxynucleotides,ODN)和自然界中细菌、病毒、无脊椎动物等低等生物的基因组DNA。CpG基序(CpG motifs)是指一类以非甲基化的胞嘧啶和鸟嘌呤核苷酸为核心的寡聚脱氧核糖核苷酸,其碱基排列大多遵循以下规律:5’端为2个嘌呤,3’端为2个嘧啶。研究表明,这种序列可激活多种免疫效应细胞,其特征结构如CpG核心、侧翼序列、骨架长度等都对其免疫刺激特性有重要影响。本文就其特征结构与免疫刺激特性的关系作一介绍。 相似文献
3.
4.
Convergence of Ets- and notch-related structural motifs in a heteromeric DNA binding complex 总被引：81，自引：0，他引：81
Analysis of the heteromeric DNA binding protein GABP has revealed the interaction of two distinct peptide sequence motifs normally associated with proteins located in different cellular compartments. The alpha subunit of GABP contains an 85-amino acid segment related to the Ets family of DNA binding proteins. The ETS domain of GABP alpha facilitates weak binding to DNA and, together with an adjacent segment of 37 amino acids, mediates stable interaction with GABP beta. The beta subunit of GABP contains four imperfect repeats of a sequence present in several transmembrane proteins including the product of the Notch gene of Drosophila melanogaster. These amino-terminal repeats of GABP beta mediate stable interaction with GABP alpha and, when complexed with GABP alpha, directly contact DNA. These observations provide evidence for a distinct biochemical role for the 33-amino acid repeats, and suggest that they may serve as a module for the generation of specific dimerization interfaces. 相似文献
5.
SBP基因家族是植物所特有的一类重要转录因子,由多个成员组成,主要参与植物生长、发育以及多种生理生化过程.试验在大豆基因组中鉴定49个SBP基因,被命名为GmSBP1~49.基于生物信息学手段,对大豆该基因家族49个成员的基因结构、染色体定位、蛋白保守序列、亚细胞定位、表达情况及进化关系进行分析.序列分析表明,SBP基因家族成员分散于不同染色体上,不同基因具有不同个数的外显子,其数目变异范围为1~14;该家族蛋白含有5个保守基序,尽管与SBP结构域有所重叠,但它们能形成6种不同的组织模式,这说明该基因家族序列变异较为复杂.表达分析结果显示,除GmSBP2和GmSBP11等6个基因没有相应的EST外,其余基因都有转录活性;在具有转录活性的基因中,只有GmSBP46显示出组成型表达模式,剩余基因表现出不同程度的组织特异性表达模式.拟南芥、水稻和大豆SBP蛋白的进化树揭示该家族具有8个类群,其中E类群只包括大豆SBP基因,其他类群中大豆SBP基因数目也是最多,这充分说明大豆SBP基因家族起源与进化的复杂性.研究为大豆SBP基因功能研究提供线索 相似文献
6.
The function of the c-Myc oncoprotein and its role in cell growth control is unclear. A basic region of c-Myc is structurally related to the basic motifs of helix-loop-helix (HLH) and leucine zipper proteins, which provide sequence-specific DNA binding function. The c-Myc basic region was tested for its ability to bind DNA by attaching it to the HLH dimerization interface of the E12 enhancer binding factor. Dimers of the chimeric protein, termed E6, specifically bound an E box element (GGCCACGTGACC) recognized by other HLH proteins in a manner dependent on the integrity of the c-Myc basic motif. Methylation of the core CpG in the E box recognition site specifically inhibited binding by E6, but not by two other HLH proteins. Expression of E6 (but not an E6 DNA binding mutant) suppressed the ability of c-myc to cooperate with H-ras in a rat embryo fibroblast transformation assay, suggesting that the DNA recognition specificity of E6 is related to that of c-Myc in vivo. 相似文献
7.
Chromatin has been prepared from nuclei isolated from the dinoflagellate alga Gyrodinium cohnii. This chromatin contains RNA, acid-insoluble proteins, and acid-soluble proteins; the respective ratios to amount of DNA are about 0.09, 0.48, 0.08 (by weight). Not only is the amount of acid-soluble protein associated with the DNA much less than it is in the typical eukaryote, but polyacrylamide gel electrophoresis in urea at pH 3.2 produces a banding pattern different from that of typical histones. There is one predominant band that migrates about as fast as does histone IV from corn. These findings are of interest, because the nuclear organization in the dinoflagellates appears to be intermediate between the prokaryotes and the eukaryotes. 相似文献
8.
ATM and ATR substrate analysis reveals extensive protein networks responsive to DNA damage 总被引：5，自引：0，他引：5
Matsuoka S Ballif BA Smogorzewska A McDonald ER Hurov KE Luo J Bakalarski CE Zhao Z Solimini N Lerenthal Y Shiloh Y Gygi SP Elledge SJ 《Science (New York, N.Y.)》2007,316(5828):1160-1166
Cellular responses to DNA damage are mediated by a number of protein kinases, including ATM (ataxia telangiectasia mutated) and ATR (ATM and Rad3-related). The outlines of the signal transduction portion of this pathway are known, but little is known about the physiological scope of the DNA damage response (DDR). We performed a large-scale proteomic analysis of proteins phosphorylated in response to DNA damage on consensus sites recognized by ATM and ATR and identified more than 900 regulated phosphorylation sites encompassing over 700 proteins. Functional analysis of a subset of this data set indicated that this list is highly enriched for proteins involved in the DDR. This set of proteins is highly interconnected, and we identified a large number of protein modules and networks not previously linked to the DDR. This database paints a much broader landscape for the DDR than was previously appreciated and opens new avenues of investigation into the responses to DNA damage in mammals. 相似文献
9.
Tagliabracci VS Engel JL Wen J Wiley SE Worby CA Kinch LN Xiao J Grishin NV Dixon JE 《Science (New York, N.Y.)》2012,336(6085):1150-1153
Protein phosphorylation is a fundamental mechanism regulating nearly every aspect of cellular life. Several secreted proteins are phosphorylated, but the kinases responsible are unknown. We identified a family of atypical protein kinases that localize within the Golgi apparatus and are secreted. Fam20C appears to be the Golgi casein kinase that phosphorylates secretory pathway proteins within S-x-E motifs. Fam20C phosphorylates the caseins and several secreted proteins implicated in biomineralization, including the small integrin-binding ligand, N-linked glycoproteins (SIBLINGs). Consequently, mutations in Fam20C cause an osteosclerotic bone dysplasia in humans known as Raine syndrome. Fam20C is thus a protein kinase dedicated to the phosphorylation of extracellular proteins. 相似文献
10.
作为植物中最重要的生长素外输载体,PIN家族在各种植物中都拥有众多成员。对水稻基因组的BLAST搜索获得了12个PIN家族成员,分析发现:水稻PIN基因不均衡地分布在基因组染色体上;其内含子、外显子结构类似;PIN蛋白质拥有典型的载体蛋白序列特征,即亲/疏水性反复变化,存在多次跨膜结构域;几乎所有PIN蛋白都有一个NPNXY的内化结构域和7个功能未知的基序;PIN在早期即分化为两组成员,主要区别在于中间亲水环的部分缺失;并且在后来发生了支系特异的复制事件,从而形成了众多旁系同源基因。 相似文献
11.
Making sense of eukaryotic DNA replication origins 总被引：1，自引：0，他引：1
Gilbert DM 《Science (New York, N.Y.)》2001,294(5540):96-100
DNA replication is the process by which cells make one complete copy of their genetic information before cell division. In bacteria, readily identifiable DNA sequences constitute the start sites or origins of DNA replication. In eukaryotes, replication origins have been difficult to identify. In some systems, any DNA sequence can promote replication, but other systems require specific DNA sequences. Despite these disparities, the proteins that regulate replication are highly conserved from yeast to humans. The resolution may lie in a current model for once-per-cell-cycle regulation of eukaryotic replication that does not require defined origin sequences. This model implies that the specification of precise origins is a response to selective pressures that transcend those of once-per-cell-cycle replication, such as the coordination of replication with other chromosomal functions. Viewed in this context, the locations of origins may be an integral part of the functional organization of eukaryotic chromosomes. 相似文献
12.
DNA bending has been suggested to play a role in the regulation of gene expression, initiation of DNA replication, DNA packaging, and the recognition of specific DNA sequences by proteins. It has recently been demonstrated that DNA bending can be sequence-directed. Bent DNA has also been observed as a consequence of sequence-specific binding of proteins to DNA. In this report DNA of plasmid pT181 is shown to contain a bend at the replication origin. Furthermore, this bend is enhanced by the binding of the pT181 replication initiator protein, RepC, to the origin. 相似文献
13.
Hardy WR Li L Wang Z Sedy J Fawcett J Frank E Kucera J Pawson T 《Science (New York, N.Y.)》2007,317(5835):251-256
Changes in protein-protein interactions may allow polypeptides to perform unexpected regulatory functions. Mammalian ShcA docking proteins have amino-terminal phosphotyrosine (pTyr) binding (PTB) and carboxyl-terminal Src homology 2 (SH2) domains, which recognize specific pTyr sites on activated receptors, and a central region with two phosphorylated tyrosine-X-asparagine (pYXN) motifs (where X represents any amino acid) that each bind the growth factor receptor-bound protein 2 (Grb2) adaptor. Phylogenetic analysis indicates that ShcA may signal through both pYXN-dependent and -independent pathways. We show that, in mice, cardiomyocyte-expressed ShcA directs mid-gestational heart development by a PTB-dependent mechanism that does not require the pYXN motifs. In contrast, the pYXN motifs are required with PTB and SH2 domains in the same ShcA molecule for the formation of muscle spindles, skeletal muscle sensory organs that regulate motor behavior. Thus, combinatorial differences in ShcA docking interactions may yield multiple signaling mechanisms to support diversity in tissue morphogenesis. 相似文献
14.
Differential gene expression in the gastrula of Xenopus laevis 总被引：39，自引：0，他引：39
15.
Scissors-grip model for DNA recognition by a family of leucine zipper proteins 总被引：152，自引：0，他引：152
C/EBP is a sequence-specific DNA binding protein that regulates gene expression in certain mammalian cells. The region of the C/EBP polypeptide required for specific recognition of DNA is related in amino acid sequence to other regulatory proteins, including the Fos and Jun transforming proteins. It has been proposed that these proteins bind DNA via a bipartite structural motif, consisting of a dimerization interface termed the "leucine zipper" and a DNA contact surface termed the "basic region." An evaluation of the properties of conserved amino acids within the basic region of 11 deduced protein sequences, coupled with the observation that they are located at an invariant distance from the leucine zipper, has led to the formulation of a "scissors-grip" model for DNA binding. The architectural features of this model are well suited for interaction with directly abutted, dyadsymmetric DNA sequences. Data supportive of the model were obtained with chemical probes of protein: DNA complexes. 相似文献
16.
基因组水平上拟南芥和水稻mrs2基因家族的比较系统发生分析 总被引：1，自引：0，他引：1
mrs2（mitochondrial RNA splicing2）基因是植物线粒体中Ⅱ类内含子自我剪接缺陷的抑制基因，同时参与了植物中镁离子的运输。本研究利用已经分离的植物的mrs2基因，鉴别出MRS2结构域，同时对拟南芥和水稻中的mrs2基因家族的成员进行了鉴定；利用这些基因编码的蛋白质序列构建了系统发生树，并进行了序列保守性分析，最后查找了相关基因的EST表达信息。结果表明：①系统发生分析表明拟南芥和水稻的mrs2基因的结构在拟南芥和水稻分离之前已经形成，并在分离之后按照物种特异性的方式进行了扩张；②MEME分析表明植物的Mrs2蛋白质具有高度保守的基序，并且在蛋白质中的排列顺序也大致相似；③mrs2基因在拟南芥和水稻中的表达有差异，但在部分表达上仍保持了一致性。 相似文献
17.
18.
19.
DNA-binding proteins 总被引：54，自引：0，他引：54
The structures of three proteins that regulate gene expression have been determined recently and suggest how these proteins may bind to their specific recognition sites on the DNA. One protein (Cro) is a repressor of gene expression, the second (CAP) usually stimulates gene expression, and the third (lambda repressor) can act as either a repressor or an activator. The three proteins contain a substructure consisting of two consecutive alpha helices that is virtually identical in each case. Structural and amino acid sequence comparisons suggest that this bihelical fold occurs in a number of proteins that regulate gene expression, and is an intrinsic part of the DNA-protein recognition event. The modes of repression and activation by Cro and lambda repressor are understood reasonably well, but the mode of action of CAP is still unclear. 相似文献
20.
Srikanth CV Wall DM Maldonado-Contreras A Shi HN Zhou D Demma Z Mumy KL McCormick BA 《Science (New York, N.Y.)》2010,330(6002):390-393
The enteric pathogen Salmonella enterica serovar Typhimurium causes food poisoning resulting in gastroenteritis. The S. Typhimurium effector Salmonella invasion protein A (SipA) promotes gastroenteritis by functional motifs that trigger either mechanisms of inflammation or bacterial entry. During infection of intestinal epithelial cells, SipA was found to be responsible for the early activation of caspase-3, an enzyme that is required for SipA cleavage at a specific recognition motif that divided the protein into its two functional domains and activated SipA in a manner necessary for pathogenicity. Other caspase-3 cleavage sites identified in S. Typhimurium appeared to be restricted to secreted effector proteins, which indicates that this may be a general strategy used by this pathogen for processing of its secreted effectors. 相似文献