浅析DNA双螺旋结构发现的社会条件

介绍了DNA双螺旋结构发现的背景与经过,分析了DNA双螺旋结构发现的社会条件,论述了从DNA双螺旋结构的发现过程中获得的有益启示。     

不再陌生的DNA——纪念DNA双螺旋结构发现60周年

 2013年是DNA双螺旋结构发现60周年.1953年沃森和克里克在英国《自然》杂志发表了DNA双螺旋结构的文章, 由此开启了分子生物学时代.60年来, 生命科学已经进入了后基因组时代——揭开基因的功能秘密, 蛋白质组学、功能基因组学等成为生命科学的热点.     

DNA复制从何而起——揭示人类遗传物质传递关键步骤

生命的奥秘让人困惑而着迷,人们对于生命起源和本质的探索更是坚定执着,生生不息.正因为此,科学家们破解了一个又一个生命科学的谜团. 1952年,科学家从噬菌体侵染细菌的实验中确定了DNA是遗传物质,自此之后,DNA便成了生命科学领域光彩夺目的主角.紧接着,科学家沃森和克里克发现了DNA的双螺旋结构,揭示了DNA分子是由两...     

DNA双螺旋结构模型对人类社会的影响

195 3年 ,美国遗传学家沃森 (Wetson)和英国物理学家克里克 (Crick)在英国《自然》(Natare)杂志上于 4月 2 5日发表论文 ,提出DNA双螺旋结构模型。这个发现宣告了分子生物学的诞生 ,在生命科学史上翻开了划时代的一页。给人类社会带来了巨大的影响。1　历史的回顾DNA双螺旋结构模型诞生五十年来 ,分子生物学领域出现了一系列激动人心的发现和突破 :195 6年美国生物化学家科恩伯格分离并提纯出了DNA聚合酶。 195 7年科恩伯格与美国生物化学家奥乔亚用人工合成的方法合成了DNA和RNA ,于 195 9年他们获得了诺贝尔生理学和医学奖。他们…     

DNA今年50岁

DNA结构发现50年来诞生了一大批具有世界影响和划时代意义的科学成果，如中心法则、遗传密码等等，同时也造就了一大批享誉国际的顶级科学家，而DNA双螺旋结构的发现也以各种方式影响着人类的科技和明进程。     

基因治疗前景光明

人类与疾病的斗争从来就没有停止过,随着DNA分子双螺旋结构的发现,人类对疾病的认识和治疗开始进入分子水平,基因治疗从此应运而生。     

基因学说的深化与发展

DNA双螺旋结构的建立是20世纪最为重要的发现之一。随后确立的中心法则使人们对于生命的本质有了更为深入的了解,基因克隆和重组技术则为人们提供了一种更为强大的改造自然的能力。回顾现代生物学发展的历程,可以清楚的看到,DNA作为遗传信息的载体和其双螺旋结构的发现所占据的重要地位。而对人类基因组的测序又为人们提供了一个更为广阔的视野,使得从整体上研究生命过程成为可能,从而使人们进入了“后基因组时代”。     

关于DNA双螺旋结构发现过程的再反思

半个多世纪以前,DNA双螺旋结构被发现。有意思的是,从发现的背景和过程来看,分子生物学这一学科不是由传统的生物学者建立的,而是由一群物理学家(晶体学家)缔造的。     

生物技术研究的新进展(上)

40多年前,沃森(Watson.J.)和克里克(Crick.F)发现了DNA双螺旋结构.从此诞生了一门新学科—分子生物学.分于生物学一诞生.就以惊人的速度发展起来.成了本世纪最重要的学科之一。生物技术的研究也因此得到高速的发展。 一、人类首创具有生命活力的     

量子生物学简介

十九世纪末,在物理学、化学发展的基础上,尤其是电子的发现、电子显微镜的发明和电子计算机的出现,使生物学从宏观现象的描述阶段转到细胞水平和亚细胞水平.二十世纪又进入了分子水平,这就使生物学跨入了近代科学的行列.1945年发现DNA(脱氧核糖核酸)分子空间构型的规律和1953年确定DNA的双螺旋结构,为量子生物学诞生提供了理论基础.量子生物学是用量子力学的原理来阐明生物大分子的结构及其功能,并进一步阐明细胞     

新课程背景下高中生物思想模型的建构探讨

本文结合自身的教学实际,以DNA分子的双螺旋结构模型为例,探讨了生物思想模型的建构过程和方法,论述了生物思想模型的教育价值。     

新课程背景下高中生物思想模型的建构探讨

本文结合自身的教学实际,以DNA分子的双螺旋结构模型为例,探讨了生物思想模型的建构过程和方法,论述了生物思想模型的教育价值。     

The conformation of the DNA double helix in the crystal is dependent on its environment

Studies of the crystal structures of more than 30 synthetic DNA fragments have provided structural information about three basic forms of the double helix: A-, B- and Z-form DNA. These studies have demonstrated that the DNA double helix adopts a highly variable structure which is related to its base sequence. The extent to which such observed structures are influenced by the crystalline environment can be found by studying the same molecule in different crystalline forms. We have recently crystallized one particular oligomer in various crystal forms. Here we report the results of structural analyses of the different crystal structures and demonstrate that the DNA double helix can adopt a range of conformations in the crystalline state depending on hydration, molecular packing and temperature. These results have implications on our understanding of the influence of the environment on DNA structure, and on the modes of DNA recognition by proteins.     

DNA打开生命之门 —— 遗传、发育与进化

DNA分子双螺旋结构的揭示直接引导现代生命科学的基础理论——中心法则建立。在过去的短短的50年中,生命科学发生了“脱胎换骨”的变化,几乎所有的传统生命科学分支学科都获得了长足的进步,许多新兴的生物学分支学科和边缘学科相继建立,生物学技术引发了社会产业结构的深刻变革,许多生物学观念也已经渗透到社会生活的各个方面,它所打开的探索生命奥秘之门将继续引领人们去挑战更多的未解的生命之谜。     

DNA 分子中热变现象的简化动力学模型探索

在用非平衡态输运理论对ＤＮＡ分子的热变现象进行描述与研究的基础上,力图寻求一个能较全面考虑ＤＮＡ分子结构及其动力学行为的较为合理的简化动力学模型,并期望此模型不但能描述ＤＮＡ分子的整体热变性质,而且还能描述ＤＮＡ局部热变,以便能进一步探索热变的动力学机制,是用理论物理方法探讨生物学现象的初步尝试。     

Recognition of DNA damage by the Rad4 nucleotide excision repair protein

Mutations in the nucleotide excision repair (NER) pathway can cause the xeroderma pigmentosum skin cancer predisposition syndrome. NER lesions are limited to one DNA strand, but otherwise they are chemically and structurally diverse, being caused by a wide variety of genotoxic chemicals and ultraviolet radiation. The xeroderma pigmentosum C (XPC) protein has a central role in initiating global-genome NER by recognizing the lesion and recruiting downstream factors. Here we present the crystal structure of the yeast XPC orthologue Rad4 bound to DNA containing a cyclobutane pyrimidine dimer (CPD) lesion. The structure shows that Rad4 inserts a beta-hairpin through the DNA duplex, causing the two damaged base pairs to flip out of the double helix. The expelled nucleotides of the undamaged strand are recognized by Rad4, whereas the two CPD-linked nucleotides become disordered. These findings indicate that the lesions recognized by Rad4/XPC thermodynamically destabilize the Watson-Crick double helix in a manner that facilitates the flipping-out of two base pairs.     

Structure of an adenine-cytosine base pair in DNA and its implications for mismatch repair

Mutational pathways rely on introducing changes in the DNA double helix. This may be achieved by the incorporation of a noncomplementary base on replication or during genetic recombination, leading to substitution mutation. In vivo studies have shown that most combinations of base-pair mismatches can be accommodated in the DNA double helix, albeit with varying efficiencies. Fidelity of replication requires the recognition and excision of mismatched bases by proofreading enzymes and post-replicative mismatch repair systems. Rates of excision vary with the type of mismatch and there is some evidence that these are influenced by the nature of the neighbouring sequences. However, there is little experimental information about the molecular structure of mismatches and their effect on the DNA double helix. We have recently determined the crystal structures of several DNA fragments with guanine X thymine and adenine X guanine mismatches in a full turn of a B-DNA helix and now report the nature of the base pairing between adenine and cytosine in an isomorphous fragment. The base pair found in the present study is novel and we believe has not previously been demonstrated. Our results suggest that the enzymatic recognition of mismatches is likely to occur at the level of the base pairs and that the efficiency of repair can be correlated with structural features.     

回顾DNA双螺旋发现的里程碑意义

从研究资源分配的调整、研究模式的转变和对科学、技术与社会的影响三个方面讨论了DNA双螺旋模型提出的里程碑意义。提出科学与技术的进步是无可阻挡的,人类的理性之光总会驱走黑暗,为世界带来更加美好的明天。     

Crystal structure of 15-mer DNA duplex containing unpaired bases

Errors during DNA replication or repair can lead to the presence of unpaired or inserted bases in the double helix, as well as to mismatched base pairs. So far only structures of the latter type have been characterized by X-ray crystallography. We report here a 3-A crystal structure of DNA 15-mer d(CGCGAAATTTACGCG), which forms a duplex with two unpaired adenine residues looped outside the B-type helix. This arrangement is in disagreement with the nuclear magnetic resonance spectroscopy results for the same 15-mer in solution, indicating polymorphic nature of the structure adopted by this sequence.