Open reading frame

As an open reading frame ( ORF ), or open reading frame ( as a translation of Engl. Open reading frame, ORF) of the portion of the DNA or mRNA is isolated in the genetics denotes the reading frame between a start codon and the first in the same reading frame following the stop codon is located. The open reading frame potentially encodes for the amino acid sequence of a peptide ( a short sequence) or protein ( long sequence).

Open reading frames are surrounded by non-coding regions of the gene, the 5 ' UTR region and the 3' UTR region. UTR stands for untranslated region. This however, is not encoding an amino acid sequence to regions of a gene which, although transcribed into mRNA in transcription in the translation. In these ranges important information for the translation of the open reading frame.

Bacterial mRNAs often carry multiple ORFs in a transcriptional unit. In this case it is called an operon, and the mRNA is called a polycistronic.

In eukaryotic genes, the ORF is often interrupted by introns spliced ​​out are ( cut out ) during the processing of the mRNA. Alternative splicing as a variety of protein variants are possible.