KOALA (KEGG Orthology And Links Annotation) was originally developed as KEGG's internal annotation tool for KO (K number) assignment using SSEARCH computation. Three variants of this tool are available for assigning K numbers to the user's sequence data: BlastKOALA and GhostKOALA using BLAST and GHOSTX searches, respectively, and KofamKOALA served by GenomeNet using the HMM profile search. The new version of BlastKOALA introduced on April 1, 2023 searches a small subset of KEGG GENES containing KEGG reference genomes and individual sequences linked from pubmed records of KO entries, rather than a much larger nonredundant dataset [1].    See Step-by-step Instructions.

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Upload query amino acid sequences in FASTA format

Enter FASTA sequences

Or upload file:

Your query data consisting of multiple amino acid sequences will be given K numbers by BlastKOALA.
Up to 50,000 sequences may be uploaded.

Enter KEGG GENES database file to be searched

Eukaryotes
Prokaryotes
Viruses

Prokaryotes and eukaryotes contain sequences of KEGG reference genomes and sequences linked from pubmed records of KO data. The size of each dataset is about 600-700 thousand sequences.

Enter your email address (institutional only, no free emails)

An email will be sent to you for confirmation of your input data. You will have to click on the link in the email to initiate your job. When the job is finished, you will receive another email for browsing the result and performing KEGG Mapper analysis. You cannot request another job until the current one is finished or canceled.   Notice: Your email address will not be used for any other purpose.

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Reference

1. Kanehisa, M., Sato, Y., and Morishima, K.; BlastKOALA and GhostKOALA: KEGG tools for functional characterization of genome and metagenome sequences. J. Mol. Biol. 428, 726-731 (2016). [pubmed] [pdf]