HydDB provides access to an accurate classifier for hydrogenase sequences and a curated database of hydrogenases by known type. The service is provided by the School of Biological Sciences, Monash University and the Bioinformatics Research Centre, Aarhus University.


If enabled, HydDB will use CDD to check whether the submitted sequences encode catalytic subunits of putative before classification. Since this step is time-consuming, you may want to uncheck this option if you are certain your sequences encode hydrogenase catalytic subunits.

If an e-mail address is provided, a mail will be sent when the job succeeds or fails.


To use the classifier to predict the type of one or more hydrogenases from sequence, either:

  • paste your FASTA-formatted protein sequences into the text area, or
  • upload a FASTA-formatted file with your protein sequences.

Press the "Submit" button to upload the sequences and begin the classification.

If you provided an e-mail address you will receive an e-mail when your job finishes or fails including a link to the results. You will also be able to download the results as a CSV file.

Only sequences encoding the catalytic subunits of hydrogenases will be classified, i.e. those binding the [NiFe]-centre (NiFe-hydrogenases), [FeFe]-centre (FeFe-hydrogenases), or [Fe]-centre (Fe-hydrogenases). Electron-transfer subunits, accessory proteins, and maturation factors cannot be classified by this service.


A job can at most run for 2 hours and atmost 4000 sequences can be submitted. This should be enough for about 2500 sequences to be classified. Results will be stored for 2 weeks. However, we recommend to download the results as they may be deleted due to the rare event of a power outage or server crash.


Jobs completed in total 3887
Sequences classified in total 1914474
Jobs completed in the last 24 hours 18
Sequences classified in the last 24 hours 29