Definition of Feature Key

The feature keys used and recommended for DDBJ submissions are as follows.

For further information of INSDC feature keys, read:
The DDBJ/EMBL/GenBank Feature Table Definition:
7.2 Appendix II: Feature keys reference.

assembly_gap
[Japanese]

gap between two components of a CON record that is part of a genome assembly

C_region
[Japanese]

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.

CDS
[Japanese]

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.

centromere
[Japanese]

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

D_segment
[Japanese]

Diversity segment of immunoglobulin heavy chain, and
T-cell receptor beta chain.

enhancer
[Japanese]

a cis-acting sequence that increases the utilization of (some) eukaryotic promoters, and can function in either orientation and in any location (upstream or downstream) relative to the promoter

exon
[Japanese]

region of genome that codes for portion of spliced mRNA, rRNA and tRNA

gap
[Japanese]

gap in the sequence; sequencing gap other than assembly_gap

intron
[Japanese]

a segment of DNA that is transcribed, but removed from within the transcript by splicing together the sequences (exons) on either side of it

J_segment
[Japanese]

Joining segment of immunoglobulin light and heavy chains, and T-cell receptor alpha, beta, and gamma chains.

LTR
[Japanese]

long terminal repeat, a sequence directly repeated at both ends of a defined sequence, of the sort typically found in retroviruses

mat_peptide
[Japanese]

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)

misc_binding
[Japanese]

site in nucleic acid which covalently or non-covalently binds another moiety that cannot be described by any other Binding key (primer_bind or protein_bind)

misc_difference
[Japanese]

feature sequence is different from that presented in the entry and cannot be described by any other "difference" key (conflict, unsure, old_sequence, mutation, or modified_base)
Comment
The misc_difference feature should be used to describe variability that arises as a result of genetic manipulation (e.g. site directed mutagenesis).

misc_feature
[Japanese]

region of biological interest which cannot be described by any other feature key; a new or rare feature.

misc_RNA
[Japanese]

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 and tRNA

misc_signal
[Japanese]

any region containing a signal controlling or altering gene function or expression that cannot be described by other "Signal" keys (promoter, CAAT_signal, TATA_signal, -35_signal, -10_signal, GC_signal, RBS, polyA_signal, enhancer, attenuator, terminator, and rep_origin)

misc_structure
[Japanese]

any secondary or tertiary nucleotide structure or conformation that cannot be described by other "Structure" keys (stem_loop and D-loop)

mobile_element
[Japanese]

region of genome sequence containing mobile element

modified_base
[Japanese]

the indicated nucleotide is a modified nucleotide and should be substituted for by the indicated molecule (given in the mod_base qualifier value)

mRNA
[Japanese]

messenger RNA; includes 5'untranslated region (5'UTR), coding sequences (CDS, exon) and 3'untranslated region (3'UTR)

ncRNA
[Japanese]

a non-protein-coding gene, other than ribosomal RNA and transfer RNA, the functional molecule of which is the RNA transcript

operon
[Japanese]

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

oriT
[Japanese]

iorigin of transfer; region of a DNA molecule where transfer is initiated during the process of conjugation or mobilization

precursor_RNA
[Japanese]

any RNA species that is not yet the mature RNA product; may include 5' untranslated region (5'UTR), coding sequences (CDS, exon), intervening sequences (intron), and 3' untranslated region (3'UTR)

primer_bind
[Japanese]

Non-covalent primer binding site for initiation of replication, transcription, or reverse transcription. Includes site(s) for synthetic e.g., PCR primer elements

promoter
[Japanese]

region on a DNA molecule involved in RNA polymerase binding to initiate transcription

protein_bind
[Japanese]

non-covalent protein binding site on nucleic acid

RBS
[Japanese]

ribosome binding site

repeat_region
[Japanese]

region of genome containing repeating units

rep_origin
[Japanese]

origin of replication; starting site for duplication of nucleic acid to give two identical copies

rRNA
[Japanese]

mature ribosomal RNA; the RNA component of the ribonucleoprotein particle (ribosome) which assembles amino acids into proteins

sig_peptide
[Japanese]

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

source
[Japanese]

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

stem_loop
[Japanese]

hairpin; a double-helical region formed by base-pairing between adjacent (inverted) complementary sequences in a single strand of RNA or DNA

telomere
[Japanese]

region of biological interest identified as a telomere and which has been experimentally characterized

terminator
[Japanese]

sequence of DNA located either at the end of the transcript that causes RNA polymerase to terminate transcription

tmRNA
[Japanese]

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;