Feature Key           sig_peptide

Definition           信号肽编码序列；一段分泌蛋白N端的编码序列；这段区域包括趋向膜的粘附初始多肽；前导序列

Optional qualifiers   /citation=[number]
                      /db_xref="<database>:<identifier>"                     
                      /evidence=<evidence_value>
                      /function="text"
                      /gene="text"
                      /label=feature_label
                      /map="text"
                      /note="text"
                      /partial
                      /product="text"
                      /pseudo
                      /standard_name="text"
                      /usedin=accnum:feature_label

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Feature Key           snRNA

Definition            小核RNA；所有的小核RNA都存在于核中；几种snRNA由剪切或其它的RNA加工过程产生

Optional qualifiers   /citation=[number]
                      /db_xref="<database>:<identifier>"                     
                      /evidence=<evidence_value>
                      /function="text"
                      /gene="text"
                      /label=feature_label
                      /map="text"
                      /note="text"
                      /partial
                      /product="text"
                      /pseudo
                      /standard_name="text"
                      /usedin=accnum:feature_label

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Feature Key           source

Definition           表明序列的特定范围的生物来源。这个关键词是必须填写的，即使所输入的序列只有一个source每个序列必须有一个以上的source.

Mandatory qualifiers  /organism="text"

Optional qualifiers   /cell_line="text"
                      /cell_type="text"
                      /chloroplast
                      /chromoplast
                      /chromosome="text"
                      /citation=[number]
                      /clone="text"
                      /clone_lib="text"
                      /country="any country from http://www.ncbi.nlm.nih.gov/collab/country.html"
                      /cultivar="text"
                      /cyanelle="text"
                      /db_xref="<database>:<identifier>"                     
                      /dev_stage="text"                     
                      /evidence=<evidence_value>
                      /focus="text"
                      /frequency="text"
                      /germline
                      /haplotype="text"
                      /lab_host="text"
                      /insertion_seq="text"
                      /isolate="text"
                      /kinetoplast
                      /label=feature_label
                      /macronuclear
                      /map="text"
                      /mitochondrion
                      /note="text"
                      /organelle=value
                      /plasmid="text"
                      /pop_variant="text"
                      /proviral
                      /rearranged
                      /sequenced_mol="text"
                      /serotype="text"
                      /sex="text"
                      /specimen_voucher="text"
                      /specific_host="text"
                      /strain="text"
                      /sub_clone="text"
                      /sub_species="text"
                      /sub_strain="text"
                      /tissue_lib="text"
                      /tissue_type="text"
                      /transposon="text"
                      /usedin=accnum:feature_label
                      /variety="text"
                      /virion
                     
Molecule scope        any