Paper Highlights

Organic chemistry of DNA functionalization; chromophores as DNA base substitutes versus DNA base/2'-modifications

W. Schmucker, H. A. Wagenknecht

Synlett 2012, DOI:10.1055/s-0032-1317158

Chemical synthesis allows to use nucleic acids as scaffolds for the precise arrangement of different kinds of artificial functionalities inside or along the double helix.


Template-directed synthesis in 3′- and 5′-direction with reversible termination

A. Kaiser, S. Spies, T. Lommel, C. Richert

Angew. Chem. Int. Ed. 2012, DOI:10.1002/anie.201203859

Ein Verfahren für die templatgesteuerte Festphasensynthese von DNA mit Phosphorsäureamid-Rückgrat wird beschrieben.
Kettenwachstum kann am 3'- und am 5'-Terminus induziert werden.


In-stem-labeled molecular beacons for distinct fluorescent color readout

C. Holzhauser, H.-A. Wagenknecht

Angew. Chem. Int. Ed. 2011, DOI:10.1002/anie.201101968

DNA traffic lights for hybridization: An efficient energy transfer between thiazole orange and thiazole red in the DNA stem architecture yields a red fluorescence that changes to green emission upon binding to the target oligonucleotide sequence.


Efficient enzyme-free copying of all four nucleobases templated by immobilized RNA

C.Deck, M. Jauker, C. Richert

Nature Chem. 2011, DOI:10.1038/nchem.1086

The transition from inanimate materials to the earliest forms of life must have involved multiplication of a catalytically active polymer that is able to replicate. The semiconservative replication that is characteristic of genetic information transfer requires strands that contain more than one type of nucleobase. Short strands of RNA can act as catalysts, but attempts to induce efficient self-copying of mixed sequences (containing four different nucleobases) have been unsuccessful with ribonucleotides. Here we show that inhibition by spent monomers, formed by the hydrolysis of the activated nucleotides, is the cause for incomplete extension of growing daughter strands on RNA templates. Immobilization of strands and periodic displacement of the solution containing the activated monomers overcome this inhibition. Any of the four nucleobases (A/C/G/U) is successfully copied in the absence of enzymes. We conclude therefore that in a prebiotic world, oligoribonucleotides may have formed and undergone self-copying on surfaces.


Construction of a structurally defined double-stranded DNA catenane

T. L. Schmidt, A. Heckel

Nano Lett. 2011, DOI:10.1021/nl200303m

Topologically interlocked structures like catenanes and rotaxanes are promising components for the construction of molecular machines and motors. Herein we describe the construction of double-stranded DNA catenanes for DNA nanotechnology. For this, C-shaped DNA minicircle fragments were equipped with sequence-specific DNA-binding polyamides and their respective binding site. Formation of catenanes is achieved by self-assembly of two of these fragments and subsequent addition of a ring-closing oligonucleotide.