The unusual structural forms of telomere DNA, which protect the ends of chromosomes during replication, may render it vulnerable to unprecedented photodamage, possibly involving nonadjacent bases that are made proximate by folding. The G-quadruplex for the human telomere sequence consisting of a repeating d(TTAGGG) is one unusual form. Tel22, d[AGGG(TTAGGG)(3)], forms a basket structure in the ...

We previously reported the chemical synthesis of oligonucleotides containing thymine glycol, a major form of oxidative DNA damage. In the preparation of the phosphoramidite building block, the predominant product of the osmium tetroxide oxidation of protected thymidine was (5R,6S)-thymidine glycol. To obtain the building block of the other isomer, (5S,6R)-thymidine glycol, in an amount sufficie...

The functional significance of a lac operator constitutive mutation has been determined. The transition adenine-thymine to guanine-cytosine was shown to be a constitutive mutation simply because thymine contains the functionally important 5-methyl group whereas cytosine does not. The remainder of the base pair is of no consequence. The experimental approach was to synthesize various modified op...

Thymine and uracil have been shown to be rapidly catabolized by animal tissues in vitro and in vivo 1_4. Several 5-substituted halogen derivatives of uracil have also been reported to be degraded in the identical manner 5_8. S e b e s t a and coworkers 9 found that 5-substituted nitroand bromouracil inhibit the degradation of thymine and uracil by rat liver acetone powder. In a previous rep o r...

Consecutive thymine sequences were oxidized more efficiently with a mixture including potassium osmate, potassium hexacyanoferrate(III), and bipyridine than an isolated thymine, and, in particular, osmium oxidation at the 5'T of TT progressed much more rapidly, compared with those of other thymines.

Exogenous thymine must be converted to thymidine to enable a thyA (thymidylate synthase) mutant to grow. The deoxyribose in the thymidine comes from dUMP, which must first be dephosphorylated. The nucleotidase YjjG is critical for this step. A yjjG thyA mutant cannot use thymine for growth on a glucose minimal medium.

The role of thymine dimerization for previously reported U.V. induced conformational changes has been proved using acetophenone as sensitizer for the specific thymine dimerization upon irradiation at 313 nm. CD results demonstrate that formation of pyrimidine dimers cause typical conformational changes of the DNA B helix as observed on irradiation at 254 nm. Thus the primary role of adenine pho...

BACKGROUND Atopic dermatitis is the most common chronic inflammatory skin disease. A complex interaction of both genetic and environmental factors is thought to contribute to the disease. AIMS To evaluate whether single nucleotide polymorphisms in the TLR2 gene c.2258C>T (R753Q) (rs5743708) and TLR2 c.-148+1614T>A (A-16934T) (rs4696480) (NM_0032643) are associated with atopic dermatitis in Tu...