Tetranucleotide

Sheffield, V.C., et al., "A Collection of Tri- and Tetranucleotide Repeat Markers Used to Generate High Quality, High Resolution Human Genome-Wide Linkage Maps," Hum. Mol. Genet., 4, 1837-1844 (1995). 

If a deoxyribonucleoside 5 -monophosphate is first esterified with a bulky apolar group, and then used as the 5 -terminus for synthesis of an oligodeoxyribonucleotide, reaction products may conveniently be isolated by solvent-extraction techniques, up to about the tetranucleotide stage. 2-(4-Tritylphenyl)thioethanol (69) and 2-(4-tritylphenyl)sulphonylethanol (70) have been used for this purpose.119 For deblocking, (69) is first oxidized to (70) with iV-chlorosuccinimide and then removed with alkali. 

Figure 12.2 Two representations of a short polynucleotide (a) a detailed atom-by-atom structure of a tetranucleotide showing both the 5 and 3 ends (b) the same structure shown in a shorthand, schematic way. Both representations possess the same basic information. (Reproduced from D. Voet and J. G. Voet, Biochemistry, 3rd edn, 2004. 2004, Donald and Judith G. Voet. Reprinted with permission of John Wiley and Sons, Inc.)...

Repeat expansion Nucleotide repeats are short DNA sequences that are repeated a number of times in a row. For example, a trinucleotide repeat is made up of 3-base-pair sequences, and a tetranucleotide repeat is made up of 4-base-pair sequences. A repeat expansion is a mutation that increases the number of times that the short DNA sequence is repeated. This type of mutation can cause the resulting protein to function improperly. 

Comings, D., Gade, R., Muhleman, D., and Sverd, J. (1995) No association of a tyrosine hydroxylase gene tetranucleotide repeat polymorphism in autism, Tourette syndrome, or ADHD. Biol Psychiatry 37 484 86. 

The techniques of Nirenberg and Leder (see Glossary) have been used to measure the coding activity of uracil dimers and hydrates contained in known positions in tri- and tetranucleotides.148 Mixtures of... 

Bolli, M., Micura, R., and Eschenmoser, A. (1997a). Ryranosyl-RNA chiroselective self-assembly of base sequences by ligative oligomerization of tetranucleotide-2, 3 -cyclophosphates (with a commentary concerning the origin of biomolecular homochirality). Chem. Biol, 4, 309-20. 

FIGURE 27-6 Effect of a termination codon in a repeating tetranucleotide. Termination codons (pink) are encountered every fourth codon in three different reading frames (shown in different colors). Dipeptides or tripeptides are synthesized, depending on where the ribosome initially binds. 

Netropsin lying in the minor groove of B-DNA hydrogen-bonded to bases in the central ATAT tetranucleotide. From Coll et al,r... 

Figure 7. Daughter ion spectrum from the m/z 134 anion isolated from the tetranucleotide deoxy(adenosine-guanosine-cytidine-thymidine). Ions were generated by laser desorption from a direct insertion probe.

Cantafora, A., Blotta, I., Bruzzese, N., Calandra, S., Bertolini, S., Rapid sizing of microsatellite alleles by gel electrophoresis on microfabricated channels application to the D19S394 tetranucleotide repeat for cosegregation study of familial hypercholesterolemia. Electrophoresis 2001, 22(18), 4012—4015. 

Tetranucleotides containing dG dC base pairs form stable duplexes at low temperature so that the self-complementary sequences dC-dC-dG-dG [contains dC(3 -5 )dG but no dG(3 -5 )dC binding sites] and dG-dG-dC-dC [contains dG(3 -5 )dC but no dC(3 -5 )dG binding sites] serve as excellent oligonucleotide duplexes for differentiating pyrimidine(3 -5 )purine specificity from purine(3 -5 )pyrimidine specificity associated with drug complexation (66, 67). ... 

Sequence Specificity We have monitored the 477 nm absorbance of 0.02 mM daunomycin on gradual addition of sequence specific tetranucleotides in 0.1 M phosphate at 1°C. The binding curves are similar for dC-dC-dG-dG and dG-dG-dC-dC at this temperature (Figure 31) and hence daunomycin does not appear to discriminate between pyrimidine(3 -5 )purine and purine(3 -5 )pyrimidine binding sites at the tetranucleotide duplex level in solution. 

Part of Chargaffs intent was to disprove the tetranucleotide hypothesis this was the idea that DNA was a monotonous tetranucleotide polymer (AGCT)re and therefore not capable of containing sequence information. Although the data presented above show that DNA cannot be simply a tetranucleotide—if so, all samples would have molar ratios of 0.25 for each base—it was still possible that the DNA from different organisms was a slightly more complex, but still monotonous, repeating sequence. 

A TETRANUCLEOTIDE WITH THE GENERAL STRUCTURE OF DNA. Test yourself on the concepts in this figure at OrganicChemistryNow. 

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