The Enzyme Database


Quick-Start Guide

General: Any word in any field can be used as the search term. While the results are output as formatted HTML, you enter the term in plain ASCII. For example, you can enter either "tRNATyr", or "trnatyr" when searching for "tRNATyr". Greek letters should be written as their English equivalent, e.g., "alpha", "beta", etc.

Menu Options


Using this feature, you can carry out the following types of searches

1. By entering an EC number, e.g., in the search field and clicking on EC number, only the entry for EC will be returned

2. Entering the same EC number but not limiting the search to the EC-number field yields far more results. These results include all those enzyme entries that refer to EC as well as enzymes with EC numbers containing "" such as EC, EC etc.

3. You can search for a number of discrete EC numbers using the regular-expression feature. For example, entering "(|" as the search term and clicking on both the regular-expression and EC Number buttons returns those two entries

4. You can view all enzymes in a class, sub-class or sub-subclass by using a wildcard as part of the search string. For example, entering "1.2.3.*" as the search term (and limiting the search to the EC number field) will return all enzyme entries within that sub-subclass

You can also choose which fields should be displayed in the output. By default, all fields present in the database are provided in the results, but you could search by EC number and then choose to view only the EC number and the systematic name in the output. To do this, you click on the field names that you want in the output in the section "and display". You can also choose to have the search term highlighted in all results by clicking on the [highlight matches] button.

Once results are returned, an additional option is available. Clicking on the "Print version" button outputs the results in black and white, in a smaller font and without the Links to other Databases field.

Enzymes By Class

With this feature, you can view all of the enzymes within a particular class, subclass or sub-subclass. The entries are stored in a hierarchical fashion.

By clicking on the    icon, you can go from the class information to information on subclasses and subsubclasses. Clicking on the hyperlink to the left of the    icon gives all results found for that element, e.g. all of the enzymes in EC 1. Clicking on the hyperlink on the right of the    icon provides a description of that class, subclass or sub-subclass in a separate window.

1. To view all enzyme entries in class 1, the oxidoreductases, click on EC 1.

2. To view the subclasses within EC 1, click on the    button, which will expand the list to show all of the available subclasses. Again, if you click on, e.g. EC 1.1, all enzymes in this subclass will be returned

3. To view all sub-subclasses within a subclass, click on the    button to the right of the relevant subclass and again you can view all entries in a given sub-subclass by clicking on the EC number, e.g. 1.1.2. Sub-subclasses that contain no current entries (only deleted/transferred entries) are greyed out but their contents can still be obtained using the    icon.

Quick Search

You can find a particular EC number quickly using two methods. On the Home page, enter the EC number you wish to find in the text box and press return.

Alternatively, you can type the URL "", replacing x.y.z.w with the EC number you are searching for.

New/Amended Enzymes

Before a new enzyme is added to the official Enzyme List, it undergoes a two-month public-review process, during which time, the entry may be modified or considered unsuitable for inclusion in the official list. Existing enzyme entries that have been modified substantially also go through this public-review process. Your feedback on these enzyme entries is particularly important to ensure that they are as correct as possible. While new enzymes are undergoing public review, the EC number should not be cited.

Until now, new/amended enzymes underwent public review in batches every two months. However, to speed up the process between submission of an enzyme entry and its inclusion in the official Enzyme List, we now plan to add individual entries to this section of the database. The date on which an enzyme is to be made official will also be included.

Advanced Search

The Advanced Search featureallows you to search for different text patterns in up to four fields at once, using Boolean algebra to include or exclude terms from the selected fields.

For example, to find all enzymes that use geranyl diphosphate but not farnesyl diphosphate as a substrate/product, enter "geranyl diphosphate" in the first search field and limit the search to the reaction field using the scroll-down menu. In the second search field, select NOT from the leftmost scroll-down menu, enter "farnesyl diphosphate" as the search term and limit the search to the reaction field.


The numbers of current, deleted and transferred entries are provided here. Clicking on each of the numbers returns all of the entries in the selected category.


The Enzyme List is updated regularly, often as a result of information provided by members of the scientific community. Two forms are available for the online submission of information: one for data on enzymes that are missing from the Enzyme List and the other for information about errors in an enzyme entry or updates that should be made.