In Principle, How Many Reading Frames in Rna Can Potentially Be Translated Into Proteins?

Analogy of possible reading frames:

AGG·TGA·CAC·CGC·AAG·CCT·TAT·ATT·AGC
A ·GGT·GAC·ACC·GCA·AGC·CTT·ATA·TTA ·GC
AG ·GTG·ACA·CCG·CAA·GCC·TTA·TAT·TAG· C

In molecular biology, a reading frame is a fashion of dividing the sequence of nucleotides in a nucleic acid (DNA or RNA) molecule into a set up of consecutive, non-overlapping triplets. Where these triplets equate to amino acids or stop signals during translation, they are called codons.

A single strand of a nucleic acrid molecule has a phosphoryl finish, chosen the 5′-end, and a hydroxyl or three′-end. These define the 5′→three′ management. There are 3 reading frames that tin can be read in this 5′→three′ management, each beginning from a dissimilar nucleotide in a triplet. In a double stranded nucleic acid, an additional three reading frames may be read from the other, complementary strand in the v′→3′ direction along this strand. As the ii strands of a double-stranded nucleic acid molecule are antiparallel, the v′→three′ direction on the 2d strand corresponds to the 3′→5′ direction along the first strand.^{[1] [2]}

In general, at the near, one reading frame in a given department of a nucleic acrid, is biologically relevant (open up reading frame). Some viral transcripts can be translated using multiple, overlapping reading frames. There is one known example of overlapping reading frames in mammalian mitochondrial Dna: coding portions of genes for two subunits of ATPase overlap.

An instance of a six-frame translation

Genetic lawmaking [edit]

DNA encodes poly peptide sequence by a series of 3-nucleotide codons. Any given sequence of DNA tin therefore be read in vi different ways: Three reading frames in one management (starting at unlike nucleotides) and three in the opposite management. During transcription, the RNA polymerase read the template Deoxyribonucleic acid strand in the 3′→5′ direction, but the mRNA is formed in the 5′ to 3′ direction.^[3] The mRNA is single-stranded and therefore only contains 3 possible reading frames, of which only one is translated. The codons of the mRNA reading frame are translated in the 5′→3′ direction into amino acids by a ribosome to produce a polypeptide concatenation.

Open reading frame [edit]

An open reading frame (ORF) is a reading frame that has the potential to be transcribed into RNA and translated into protein. Information technology requires a continuous sequence of Dna from a start codon, through a subsequent region which usually has a length that is a multiple of 3 nucleotides, to a finish codon in the same reading frame.^[4]

When a putative amino acrid sequence resulting from the translation of an ORF remained unknown in mitochondrial and chloroplast genomes, the corresponding open reading frame was called an unidentified reading frame (URF). For example, the MT-ATP8 gene was first described as URF A6L when the complete human mitochondrial genome was sequenced.^[5]

Multiple reading frames [edit]

The two reading frames used by the human mitochondrial genes MT-ATP8 and MT-ATP6.

The usage of multiple reading frames leads to the possibility of overlapping genes; in that location may exist many of these in viral, prokaryote, and mitochondrial genomes.^[six] Some viruses, east.thousand. hepatitis B virus and BYDV, employ several overlapping genes in different reading frames.

In rare cases, a ribosome may shift from 1 frame to another during translation of an mRNA (translational frameshift). This causes the first role of the mRNA to be translated in one reading frame, and the latter part to exist translated in a different reading frame. This is distinct from a frameshift mutation, as the nucleotide sequence (Dna or RNA) is not altered—only the frame in which it is read.

Encounter too [edit]

• Genetic code
• Directionality (molecular biology)
• Sense (molecular biological science)

References [edit]

1. ^ Rainey South, Repka J. "Quantitative sequence and open reading frame analysis based on codon bias" (PDF). Systemics, Cybernetics and Informatics. 4 (1): 65–72.
2. ^ Annoy JH, Olsen GJ (April 1999). "CRITICA: Coding Region Identification Tool Invoking Comparative Analysis". Mol Biol Evol. 16 (iv): 512–24. doi:ten.1093/oxfordjournals.molbev.a026133. PMID 10331277.
3. ^ Lodish (2007). Molecular Prison cell Biology (6th ed.). West. H. Freeman. p. 121. ISBN978-1429203142.
4. ^ Benjamin C. Pierce (2012). Genetics: a conceptual approach. Due west. H. Freeman. ISBN9781429232500.
5. ^ Anderson Southward, Bankier AT, Barrell BG, de Bruijn MH, Coulson AR, Drouin J, Eperon IC, Nierlich DP, Roe BA, Sanger F, Schreier PH, Smith AJ, Staden R, Young IG (April 1981). "Sequence and organization of the human being mitochondrial genome". Nature. 290 (5806): 457–65. Bibcode:1981Natur.290..457A. doi:10.1038/290457a0. PMID 7219534.
6. ^ Johnson Z, Chisholm South (2004). "Properties of overlapping genes are conserved beyond microbial genomes". Genome Res. 14 (11): 2268–72. doi:ten.1101/gr.2433104. PMC525685. PMID 15520290.

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Source: https://en.wikipedia.org/wiki/Reading_frame

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