GENETIC_CODE {Biostrings}R Documentation

The Standard Genetic Code

Description

Two predefined objects (GENETIC_CODE and RNA_GENETIC_CODE) that represent The Standard Genetic Code.

Usage

GENETIC_CODE
RNA_GENETIC_CODE

Details

Formally, a genetic code is a mapping between tri-nucleotide sequences called codons, and amino acids.

The Standard Genetic Code (aka The Canonical Genetic Code, or simply The Genetic Code) is the particular mapping that encodes the vast majority of genes in nature.

GENETIC_CODE and RNA_GENETIC_CODE are predefined named character vectors that represent this mapping.

Value

GENETIC_CODE and RNA_GENETIC_CODE are both named character vectors of length 64 (the number of all possible tri-nucleotide sequences) where each element is a single letter representing either an amino acid or the stop codon "*" (aka termination codon).

The names of the GENETIC_CODE vector are the DNA codons i.e. the tri-nucleotide sequences (directed 5' to 3') that are assumed to belong to the "coding DNA strand" (aka "sense DNA strand" or "non-template DNA strand") of the gene.

The names of the RNA_GENETIC_CODE are the RNA codons i.e. the tri-nucleotide sequences (directed 5' to 3') that are assumed to belong to the mRNA of the gene.

Note that the values in the GENETIC_CODE and RNA_GENETIC_CODE vectors are the same, only their names are different. The names of the latter are those of the former where all occurrences of T (thymine) have been replaced by U (uracil).

Author(s)

H. Pages

References

http://www.ncbi.nlm.nih.gov/Taxonomy/Utils/wprintgc.cgi

See Also

AA_ALPHABET, AMINO_ACID_CODE, translate, trinucleotideFrequency, DNAString, RNAString, AAString

Examples

  GENETIC_CODE
  GENETIC_CODE[["ATG"]]  # codon ATG is translated into M (Methionine)
  sort(table(GENETIC_CODE))  # the same amino acid can be encoded by 1
                             # to 6 different codons

  RNA_GENETIC_CODE
  all(GENETIC_CODE == RNA_GENETIC_CODE)  # TRUE

[Package Biostrings version 2.22.0 Index]