The feature keys used and recommended for DDBJ submissions are as follows.
Constant region of immunoglobulin light and heavy chains, and T-cell receptor alpha, beta, and gamma chains.
Includes one or more exons depending on the particular chain.
coding sequence; sequence of nucleotides that corresponds with the sequence of amino acids in a protein (location includes stop codon).
See also the page about CDS feature.
region of biological interest identified as a centromere and which has been experimentally characterized
displacement loop; a region within mitochondrial DNA in which a short stretch of RNA is paired with one strand of DNA, displacing the original partner DNA strand in this region;
also used to describe the displacement of a region of one strand of duplex DNA by a single stranded invader in the reaction catalyzed by RecA protein
Diversity segment of immunoglobulin heavy chain, and T-cell receptor beta chain.
gap in the sequence; sequencing gap other than assembly_gap
a segment of DNA that is transcribed, but removed from within the transcript by splicing together the sequences (exons) on either side of it
Joining segment of immunoglobulin light and heavy chains, and T-cell receptor alpha, beta, and gamma chains.
long terminal repeat, a sequence directly repeated at both ends of a defined sequence, of the sort typically found in retroviruses
mature peptide or protein coding sequence; coding sequence for the mature or final peptide or protein product following post-translational modification.
The location does not include the stop codon (unlike the corresponding CDS)
feature sequence is different from that presented in the entry and cannot be described by any other "difference" key;
unsure, variation, modified_base
The misc_difference feature should be used to describe variability that arises as a result of genetic manipulation (e.g. site directed mutagenesis).
region of biological interest which cannot be described by any other feature key; a new or rare feature.
any transcript or RNA product that cannot be defined by other RNA keys
prim_transcript, precursor_RNA, mRNA, 5'UTR, 3'UTR, exon, CDS, sig_peptide, transit_peptide, mat_peptide, intron, polyA_site, ncRNA, rRNA, tRNA, tmRNA
region of genome sequence containing mobile element
the indicated nucleotide is a modified nucleotide and should be substituted for by the indicated molecule (given in the mod_base qualifier value)
region containing polycistronic transcript including a cluster of genes that are under the control of the same regulatory sequences/promoter and in the same biological pathway
iorigin of transfer; region of a DNA molecule where transfer is initiated during the process of conjugation or mobilization
any RNA species that is not yet the mature RNA product
Non-covalent primer binding site for initiation of replication, transcription, or reverse transcription. Includes site(s) for synthetic e.g., PCR primer elements
non-covalent protein binding site on nucleic acid
any region of sequence that functions in the regulation of transcription or translation
Since December 2014, the following old features have been merged into this feature.
region of genome containing repeating units
origin of replication; starting site for duplication of nucleic acid to give two identical copies
mature ribosomal RNA; the RNA component of the ribonucleoprotein particle (ribosome) which assembles amino acids into proteins
signal peptide coding sequence; coding sequence for an N-terminal domain of a secreted protein;
this domain is involved in attaching nascent polypeptide to the membrane; leader sequence
identifies the biological source of the specified span of the sequence.
This key is mandatory. Every entry will have, as a minimum, a single source key spanning the entire sequence.
More than one source key per sequence is permissible
hairpin; a double-helical region formed by base-pairing between adjacent (inverted) complementary sequences in a single strand of RNA or DNA
region of biological interest identified as a telomere and which has been experimentally characterized
transfer messenger RNA; tmRNA acts as a tRNA first, and then as an mRNA that encodes a peptide tag;
the ribosome translates this mRNA region of tmRNA and attaches the encoded peptide tag to the C-terminus of the unfinished protein;
this attached tag targets the protein for destruction or proteolysis;
transit peptide coding sequence; coding sequence for an N-terminal domain of a nuclear-encoded organellar protein;
this domain is involved in post-translational import of the protein into the organelle
mature transfer RNA, a small RNA molecule (75-85 bases long) that mediates the translation of a nucleic acid sequence into an amino acid sequence
author is unsure of exact sequence in this region
Variable region of immunoglobulin light and heavy chains, and T-cell receptor alpha, beta, and gamma chains. Codes for the variable amino terminal portion. Can be made up from V_segments, D_segments, N_regions and J_segments.
Variable segment of immunoglobulin light and heavy chains, and T-cell receptor alpha, beta, and gamma chains. Codes for most of the variable region (V_region) and the last few amino acids of the leader peptide
a related strain contains stable mutations from the same gene (e.g., RFLPs, polymorphisms, etc.) which differ from the presented sequence at this location (and possibly others).
1) region at the 3' end of a mature transcript (following the stop codon) that is not translated into a protein;
2) region at the 3' end of an RNA virus (following the last stop codon) that is not translated into a protein;
1) region at the 5' end of a mature transcript (preceding the initiation codon) that is not translated into a protein;
2) region at the 5' end of an RNA virus genome (preceding the first initiation codon) that is not translated into a protein;