Tallography. So far, our progress in this project of selenium derivation on nucleic acids has demonstrated for the first time a new strategy to covalently derivatize nucleotides with selenium for phase and structure determination in X-ray crystallography, and have shown that the MAD phasing technique works with this selenium derivatization strategy. As one selenium atom enables phase determination for RNAs or DNAs up to 30 nt. (based on an approximate calculation of X-ray phasing power) and the frequency of a building block in a nucleotide sequence is high (25% average rate), selenium-labeled ORDERING INFORMATION
Item
FIGURE : STRUCTURE OF 2′-Se-Me-U
O HN DMTO O O N
SeMe O P N(iPr)2 O CNEt
2′-Se-Me-U
dU (mimic of T) and U building blocks should meet most of the needs for DNA and RNA derivatization. Here we present you a product that can serve as both seleniumlabeled dU and U building blocks for RNA and DNA Derivatization in X-ray Crystallography.
damage in all organisms is the UV O O component of sunlight. The CH 3 CH 3 HN HN predominant reaction induced by UV light on DNA is dimerization of O N O N CH 3O CH 3O O H O H adjacent pyrimidine bases leading O O NH NH to cyclobutane dimers (CPDs) and O O O 6-4 photoproducts. The dimers N O N H H O P O O P O formed in the most significant O O OH OH quantity are the cis-syn cyclobutane dimer of two thymine O O bases (1) and the corresponding 64 photoproduct (3). The trans-syn (1) Cis-syn Thymine Dimer (2) Trans-syn Thymine Dimer thymine dimer (2) is formed at a much lower level in single and O double stranded DNA. In sunlight, O CH 3 the 6-4 photoproduct is converted CH 3 HN HN OH OH to its Dewar isomer (4) by O N O absorption of long-wave UV light at O N N O O H N O H 1 O around 325nm. O N N Although formed routinely, H C H C O 3 H O 3 these dimer products are, O P O O P O O fortunately for us, efficiently O OH OH excised and repaired enzymatically (nucleotide excision repair) or the O O dimerization is reversed by photolase enzymes. These lesions (3) 6-4 Thymine Dimer (4) Dewar Thymine Dimer have been connected to the formation of squamous cell carcinomas. In addition, thymine dimer phosphoramidites has to humans who lack ability to repair CPD lesions with acknowledge the work of Professor Taylor and his high efficiency may be genetically predisposed to co-workers. Their contribution3 to this field has been Xeroderma Pigmentosa (XP), a disease characterized outstanding.155148-31-5 Description by extreme sensitivity to sunlight and high frequency It has been clear to us for some time that of skin cancer. Polymerases encountering unrepaired researchers into DNA damage and repair would value CPD lesions are quite error-prone, presumably the ability to produce oligonucleotides containing leading to incorrect base insertions and subsequent cis-syn thymine dimer at specific locations within mutations.137234-62-9 Biological Activity 2 the sequence.PMID:24027799 Unfortunately, the chemical processes The literature covering the chemistry of required to produce cis-syn thymine dimer thymidine dimers and other CPDs is replete with phosphoramidite are very tortuous4,5 and it was only references from John-Stephen Taylor’s group at recently that we were able to obtain this Washington University in St. Louis. Any article on (Continued on Back Page)
ERAGEN BIOSCIENCES TECHNOLOGY (courtesy of EraGen Biosciences)
In natural DNA, two complementary strands
are joined by a sequence of Watson-Crick base pairs. These obey two rules of complementarity: size (large purines pair with smaller p.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com
