序列标识图(Sequence Logo),亦称序列表志图,是一种图形化工具,用于呈现序列比对中每一位置上残基(如DNA、RNA中的碱基或蛋白质中的氨基酸)的出现频率。它能直观反映特定位置序列的保守性,即某一位点特定残基出现的频次及其稳定性。
输入文件
序列文件

输出文件

- 图形类型:序列logo图(Sequence Logo)
- X轴:序列中的碱基/氨基酸位置(Position)
- Y轴:每个位点的碱基/氨基酸信息量或频率(默认为百分比概率)
- 字母高度:每个字母(如A、T、C、G或氨基酸缩写)的高度代表其在该位点出现的频率或信息量。字母越高,说明该位点越倾向于出现该碱基/氨基酸。
- 颜色:可自定义不同字母的颜色,便于区分不同类型的碱基或氨基酸。
- 该图用于展示一组序列在各个位点上的保守性和变异性。
- 某个位点上某个字母特别高,说明该位点高度保守,几乎总是该字母。
- 如果某个位点上多个字母高度接近,说明该位点变异性大,不同序列中该位置的字母分布较为均匀。
- 常用于motif分析、转录因子结合位点分析、蛋白质结构功能研究等领域。
A sequence logo, also known as a seqlogo, is a graphical tool that visualizes the frequency of residues (such as bases in DNA, RNA, or amino acids in proteins) at each position in a sequence alignment. It intuitively reflects the conservation of sequences at specific positions, that is, the frequency and stability of specific residues at a certain position.
Input
sequence file

output

Chart Description
Chart Type: Sequence Logo
X-axis: Nucleotide/amino acid position in the sequence (Position)
Y-axis: Information content or frequency (default: percentage probability) of each nucleotide/amino acid at the given position
Letter Height: The height of each letter (e.g., A, T, C, G, or amino acid abbreviations) represents its frequency or information content at that position. A taller letter indicates a stronger preference for that nucleotide/amino acid at the given position.
Colors: Different letters can be assigned custom colors to distinguish between nucleotide/amino acid types.