seqan3::aa20 Class Reference

The canonical amino acid alphabet. More...

#include <seqan3/alphabet/aminoacid/aa20.hpp>

Inheritance diagram for seqan3::aa20:

Public Member Functions
Constructors, destructor and assignment
constexpr	aa20 () noexcept=default
	Defaulted.
constexpr	aa20 (aa20 const &) noexcept=default
	Defaulted.
constexpr	aa20 (aa20 &&) noexcept=default
	Defaulted.
constexpr aa20 &	operator= (aa20 const &) noexcept=default
	Defaulted.
constexpr aa20 &	operator= (aa20 &&) noexcept=default
	Defaulted.
	~aa20 () noexcept=default
	Defaulted.
Public Member Functions inherited from seqan3::aminoacid_base< aa20, 20 >
constexpr	aminoacid_base (other_aa_type const other) noexcept
	Allow explicit construction from any other aminoacid type and convert via the character representation.
Public Member Functions inherited from seqan3::alphabet_base< derived_type, size, char_t >
constexpr	alphabet_base () noexcept=default
	Defaulted.
constexpr	alphabet_base (alphabet_base const &) noexcept=default
	Defaulted.
constexpr	alphabet_base (alphabet_base &&) noexcept=default
	Defaulted.
constexpr alphabet_base &	operator= (alphabet_base const &) noexcept=default
	Defaulted.
constexpr alphabet_base &	operator= (alphabet_base &&) noexcept=default
	Defaulted.
	~alphabet_base () noexcept=default
	Defaulted.
constexpr char_type	to_char () const noexcept
	Return the letter as a character of char_type.
constexpr rank_type	to_rank () const noexcept
	Return the letter's numeric value (rank in the alphabet).
constexpr derived_type &	assign_char (char_type const chr) noexcept
	Assign from a character, implicitly converts invalid characters.
constexpr derived_type &	assign_rank (rank_type const c) noexcept
	Assign from a numeric value.

Related Symbols
(Note that these are not member symbols.)
using	aa20_vector = std::vector< aa20 >
	Alias for a std::vector of seqan3::aa20.

Additional Inherited Members
Static Public Member Functions inherited from seqan3::aminoacid_base< aa20, 20 >
static constexpr bool	char_is_valid (char_type const c) noexcept
	Validate whether a character value has a one-to-one mapping to an alphabet value.
Static Public Attributes inherited from seqan3::alphabet_base< derived_type, size, char_t >
static constexpr detail::min_viable_uint_t< size >	alphabet_size = size
	The size of the alphabet, i.e. the number of different values it can take.
Protected Types inherited from seqan3::alphabet_base< derived_type, size, char_t >
using	char_type = std::conditional_t< std::same_as< char_t, void >, char, char_t >
	The char representation; conditional needed to make semi alphabet definitions legal.
using	rank_type = detail::min_viable_uint_t< size - 1 >
	The type of the alphabet when represented as a number (e.g. via to_rank()).

Detailed Descriptionstable-api

The canonical amino acid alphabet.

The alphabet consists of letters A, C, D, E, F, G, H, I, K, L, M, N, P, Q, R, S, T, V, W, Y

The alphabet may be brace initialized from the static letter members (see above). Note that you cannot assign regular characters, but additional functions for this are available.

Note: Letters which belong in the extended alphabet will be automatically converted based on the frequency of their options.
Terminator characters are converted to W, because the most commonly occurring stop codon in higher eukaryotes is UGA². Anything unknown is converted to S, because it occurs most frequently across 53 vertebrates¹.

Input Letter	Converts to
B	D1
J	L1
O	L1
U	C1
Z	E1
X (Unknown)	S1
* (Terminator)	W2

¹King, J. L., & Jukes, T. H. (1969). Non-Darwinian Evolution. Science, 164(3881), 788-798. doi:10.1126/science.164.3881.788
²Trotta, E. (2016). Selective forces and mutational biases drive stop codon usage in the human genome: a comparison with sense codon usage. BMC Genomics, 17, 366. https://doi.org/10.1186/s12864-016-2692-4

// SPDX-FileCopyrightText: 2006-2025 Knut Reinert & Freie Universität Berlin
// SPDX-FileCopyrightText: 2016-2025 Knut Reinert & MPI für molekulare Genetik
// SPDX-License-Identifier: CC0-1.0
 
#include <seqan3/alphabet/aminoacid/aa20.hpp>
#include <seqan3/core/debug_stream.hpp>
 
int main()
{
    using namespace seqan3::literals;
 
    seqan3::aa20 letter{'A'_aa20};
 
    letter.assign_char('C');
    seqan3::debug_stream << letter << '\n'; // prints "C"
 
    letter.assign_char('?');                // Unknown characters are implicitly converted to S.
    seqan3::debug_stream << letter << '\n'; // prints "S"
}

This entity is stable. Since version 3.1.

Friends And Related Symbol Documentation

aa20_vector [stable-api]

using aa20_vector = std::vector<aa20>

stable-apirelated

Alias for a std::vector of seqan3::aa20.

This entity is stable. Since version 3.1.

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The documentation for this class was generated from the following file:

• aa20.hpp