以endo-beta-1,4-galactanase为例介绍其氨基酸序列调取、序列比对及建树的流程 一：序列序列调取
1. 在BRENDA（http://www.brenda-enzymes.org/）搜索酶，如下图：在搜索框内输入
“endo-beta-1,4-galactanase”选择搜索内容，如下图篮框“Enzyme”, 点击“Start search”显示搜索结果。
2. 搜索结果见下图
3. 双击红色方框，显示所搜索的酶的氨基酸序列号
4. 双击上图红色序列号，如Q9X0S8，显示搜索酶的氨基酸序列，如下图：
5. 可以下载单个序列，也可以下载所有的数据中的endo-beta-1,4-galactanase，下载序列，
保存。 二、 序列比对
1.下载到的序列比对，选用比对软件”Clustal X”比对，序列载入
2.序列比对
3.保存
三、构建系统发育树
选用MEGA6 构建系统发育树：
Mega因为操作简单，结果美观，很多研究者选择用它来建树。
(1) 首先用Clustal X进行序列比对，剪切后生成D:\\文老师\\酶\\Bifidobacterium.aln文件；
(2) 打开Mega程序，转化为mega格式并激活目标文件，
(3) File-Convert To MEGA Format- D:\\文老师\\酶\\Bifidobacterium.aln →D:\\文老师\\酶
\\Bifidobacterium. meg，
(4) Phylogeny-Neighbor-Joining(NJ) (5) Protein sequence→OK (6) 开始计算－得到结果；
I8YQW3|arabinogalactan434754 D4WP72|arabinogalactan R6J710|arabinogalactan A7M5U2|arabinogalactan100 I9HZH7|arabinogalactan F7LE03|arabinogalactan10057 A0A078PYK0|arabinogalactan R6E3H2|arabinogalactan98100 R5V2B1|arabinogalactan99 I9Q1U4|arabinogalactan92 A5ZGS0|arabinogalactan69 K5CSY8|arabinogalactan100 R6S5B4|arabinogalactan1001007899 C9L001|arabinogalactan R6V9P5|arabinogalactan D7K7G3|arabinogalactan R5VE68|arabinogalactan100 E2NMA6|arabinogalactan R6KPQ5|arabinogalactan909993 A0A069D6L5|arabinogalactan U6RAT1|arabinogalactan61 R7KK27|arabinogalactan Q89YR3|arabinogalactan100 D7IA61|arabinogalactan56 C6IQ23|arabinogalactan6885 R9H881|arabinogalactan100 A0A078QA81|arabinogalactan26 A0A078Q7X7|arabinogalactan R6ZSY5|arabinogalactan100 R5W7T5|arabinogalactan63 A0A078RXS1|arabinogalactan93 I8ZPX3|arabinogalactan43 R7EBX7|arabinogalactan4110099 A7V0W8|arabinogalactan R9HUC6|arabinogalactan39 E5VAD2|arabinogalactan K9DSN8|arabinogalactan10068100 R5S2G0|arabinogalactan R5C116|arabinogalactan69100 B0NQK4|arabinogalactan S3ZJQ9|arabinogalactan999941 D2ESG2|arabinogalactan E6SQF3|arabinogalactan R5M5U9|arabinogalactan100 R7DUP1|arabinogalactan95 I9QMG7|arabinogalactan100 R5RUK2|arabinogalactan R6E3J0|arabinogalactan5135 C3Q3U6|arabinogalactan I8WE00|arabinogalactan A0A076IYP6|arabinogalactan100 B6VYB2|arabinogalactan I9R4F8|arabinogalactan62 D1K6Z6|arabinogalactan C3RCI9|arabinogalactan A0A078RGT2|arabinogalactan D4V3H4|arabinogalactan63 C6YZ45|arabinogalactan E5UN80|arabinogalactan A0A069SNP0|arabinogalactan R2AUA8|arabinogalactan I0F933|arabinogalactan I8YPK4|arabinogalactan0.2
endo-beta-1,4-galactanase bacteroides