
Health Dictionary
Reliable, easy-to-read patient information on common medical conditions — written in plain language, free of jargon, and grounded in current evidence. Browse the most frequent diagnoses, understand what they mean for everyday life, and learn which steps and questions help you have a focused conversation with your doctor.
Reading frames
Introduction
In biology, a reading frame is a contiguous and non-overlapping set of three-nucleotide codons in DNA or RNA. There are 3 possible reading frames in a mRNA strand and six in a double stranded DNA molecule due to the two strands from which transcription is possible. This leads to the possibility of overlapping genes and there may be many of these in bacteria.[1] Some viruses e.g. HBV and BYDV use several overlapping genes in different reading frames.
In rare cases a translating ribosome may shift from one frame to another, a translational frameshift. It is distinct from a frameshift mutation as the nucleotide sequence (DNA or RNA) is not altered only the frame in which it is read.
A reading frame that contains a start codon and a stop codon is called an open reading frame (ORF).
References
References
- ↑ Johnson Z, Chisholm S (2004). “Properties of overlapping genes are conserved across microbial genomes”. Genome Res. 14 (11): 2268–72. PMID 15520290.
