鸟嘌呤

Uracil also can be introduced by hydrolytic deamination of cytosine which paired with guanine. Highly mutagenic dU:dG mispair may cause a C→T transition mutation upon replication if it was not repaired.

另一种可能则是由胞嘧啶(Cytosine； C)发生自发性或氧化脱胺反应而形成尿嘧啶与鸟粪嘌呤的配对错误。

This kind of configuration suits the multi-nucleotide chain's purine pyrimidine alternate area. in 1989, the American scientists with scanning tunnel electron microscope law visual observation double helix DNA double helix DNA ︰ in 1952, Austrian lineage US biology chemist Zha Qiefu (E.chargaff,1905-) have determined in DNA 4 kind of basic group content, the discovery gland fat ling and thymine quantity are equal, the bird fat ling and cytosine quantity is equal.

这种构型适合多核苷酸链的嘌呤嘧啶交替区。1989年，美国科学家用扫描隧道电镜法直接观察到双螺旋DNA 双螺旋DNA︰1952年，奥地利裔美国生物化学家查伽夫（E.chargaff，1905—）测定了DNA中4种碱基的含量，发现其中腺膘呤与胸腺嘧啶的数量相等，鸟膘呤与胞嘧啶的数量相等。

Based on density functional theory and electronegativity equalization principle,applying an atom-bond electronegativity equalization σπ model,using a separated program,we calculated the charge distributions and dipole moments of guanine tautomers.

以密度泛函和电负性均衡原理为基础发展的原子-键电负性均衡方法的σπ模型。并结合自编程序，计算了鸟嘌呤五种异构体的电荷分布和偶极矩，计算结果表明，所计算出的电荷分布可以和从头算结果很好地关联。所计算的偶极矩与其它从头计算方法和力场方法相比总体趋势相同，进一步说明了ABEEMσπ模型的合理性

After overcoming the flux shift during the process, the production ability of strains could be the limiting factor for further increasing the production. To avoid the random modification on strains, the comprehensive enzymatic study of nucleoside producing-pathway was conducted on four strains with different producing ability. And the results could be used to direct further reconstruction of strains. It was also found that nucleotidase was of much importance to nucleoside production.

在成功克服了代谢流的迁移之后，菌株的代谢能力可能成为了进一步提高产率的限制因素，为了避免对生产菌的进一步改造中的盲目性，对四株不同菌株间嘌呤途径关键酶活力的系统测定，对肌苷、鸟苷生产菌种的酶学特征有了全面的了解；并发现了核苷降解酶对于核苷生产能力至关重要；酶学特性研究对肌苷、鸟苷生产菌的进一步改造提供了方向。

Therefore, it is important to develop a rapid and convenient method to study released deoxyribonucleic acid of soil microorganisms and viruses.

因此，若能以迅速方便的方法来侦测鸟粪嘌呤，则对未来在土壤微生物或病毒释出去氧核醣核酸方面的探讨应具有发展潜势。

Et al.(2003) Crosstalk between Rap and Rac regulates secretion of sAPP alpha. Nat. Cell Biol. 5, 633-639. We now report that Rap1 can physically and specifically associate with the guanine nucleotide exchange factor STEF through its TSS region.

我们现在说的是Rap1可以通过它的TSS区域实质地并且特异与STEF因子的鸟嘌呤核苷酸的改变相关联。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。