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KEGG Annotation - Ortholog Table


Ortholog Table

The ortholog table (OT) has existed from the beginning of the KEGG project. For a given set of K numbers it displays the current assignment of genes in KEGG organisms and viruses.

Enter K numbers      (Example) K22014 K21512 K26964 K26963 K21511 K26962 K26961 K26965 K26966

The ortholog table additionally displays positional correlations of genes in the chromosome, such as operon structures, by coloring. The same color means that the genes are adjacent.


Module Table - Taxonomic distribution of KOs and modules

In contrast to the ortholog table, which identifies individual genes for each of the KOs, the module table (MT) displays only taxonomic distributions of KOs and modules. For a given set of M and/or K numbers it identifies organisms that contain complete modules and/or KO groups. The list of organisms may be collapsed into broader organism groups.

Enter M/K numbers      (Example) M00595 K16952 M00596

The taxonomic distribution of a single KO or module can be viewed from its entry page (such as K22014) through or button. Taxonomy mapping is performed using the default taxonomy file for cellular organsims (br08611) or viruses (br08621).


Cluster Table - Positional correlation of genes

Each GENES entry page contains either button for a cellular organism (such as ece:Z1882) or button for a virus (such as vg:40093755) showing similar genes along the chromosome. Gene names in the table are associated with K numbers assigned, and the coloring indicates adjacency of genes. Differences of the two cluster tables are the following.

Gene cluster
  • Similarity is defined by a given threshold of the SW score computed by SSEARCH (see KEGG Annotation)
  • Query gene and up to ten adjacent genes on both sides are included
Vog cluster
  • Similarity is based on computationally generated Virus ortholog group (see KEGG Virus)
  • Query gene and up to ten adjacent genes on both sides are included


Last updated: April 10, 2024