Nucleic acid nomenclature

As nucleic acid nomenclature certain abbreviations are referred to in reference to nucleic acids such as DNA and RNA in the chemistry that have been established by the IUPAC. The following definitions there in nucleic acids:

Orientation

The basic building block of nucleic acid are nucleotides. The central element is the ribose here. Based on the carbon atoms of the molecule, counting clockwise, the positions in the nucleic acid will be described. The positions are labeled according to the respective number and the 'character ( ie stroke ). For example, makes the hydroxyl group at the 2'-position of ribose, the difference between DNA and RNA. As in the nucleic acid, the hydroxy group at 3 ' is a nucleobase linked to the phosphate group of the next, the polarity and thus the orientation of a DNA / RNA strand with 5' and 3 denotes '. For example, polymerases move on the antisense strand from 3 'to 5 ' and 3 ' → 5' advertised. Other enzymes (eg some nucleases ) move the other hand, 5 '→ 3', ie from the 5 ' end toward the 3' end. Sense strands are 5 '→ 3' written, according to the reading direction of the ribosome during translation. Wherein the 5 'end in front and the 3' end is the rear. 3'-and 5' - end also serve as a criteria for identifying the orientation of genes.

Symbols of bases

The five nucleobases of DNA and RNA are abbreviated by their initials. Other symbols for non-specific nucleobase (two or more nucleobases can be used as an alternative ) to be used when no unique assignment can be made in a sequence.