Assign KO tool
The Assign KO tool is an interactive tool equivalent to the BlastKOALA server for use with a small dataset. BlastKOALA assigns KOs (K numbers) to a given set of amino acid sequences for subsequent analysis with the KEGG Mapper Reconstruct tool.
More details about this tool
Processing of BLAST search result
- Run BLASTP and extract from the output format 6 (tabular output) qseqid (query sequence id), sseqid (target sequence id), pident (percentage of identical matches), length (alignment length) and bitscore for a given threshold of evalue (0.1 for example).
- For each query sequence, create a GFIT table containing a single top-scoring sequence from each target genome.
- Compute the modified identity score: identity = pident * min(1, length*2/(aalen1+aalen2)) where aalen1 and aalen2 are the query and target sequence lengths.
- The GFIT table is grouped according to the assigned K numbers (including none assigned), and compute the weighted sum of identity scores. This may be done by looking only up to 10 hits in the GFIT table.
- Assign a K number or none according to the weighted sum.
Reference genomes in KEGG are well-curated genomes and/or representative genomes in taxonomic groups. They are not subject to automatic KOALA annotation. The reference GENES dataset is a collection of protein coding genes in reference genomes and publication-based sequence data associated with KOs, many of which are in the GENES Addendum (ag) category.
Last updated: December 1, 2025