clusterProfiler can convert biological IDs using OrgDb object via the bitr function. Now I implemented another function, bitr_kegg for converting IDs through KEGG API.

The ID type (both fromType & toType) should be one of 'kegg', 'ncbi-geneid', 'ncbi-proteinid' or 'uniprot'. The 'kegg' is the primary ID used in KEGG database. The data source of KEGG was from NCBI. A rule of thumb for the 'kegg' ID is entrezgene ID for eukaryote species and Locus ID for prokaryotes.

Many prokaryote species don't have entrezgene ID available. For example we can check the gene information of ece:Z5100 in http://www./dbget-bin/www_bget?ece:Z5100, which have NCBI-ProteinID and UnitProt links in the Other DBs Entry, but not NCBI-GeneID.

If we try to convert Z5100 to ncbi-geneid, bitr_kegg will throw error of ncbi-geneid is not supported.

We can of course convert it to ncbi-proteinid and uniprot:

search_kegg_organism

clusterProfiler supports more than 4k species listed in http://www./kegg/catalog/org_list.html for hypergeometric test (enrichKEGG & enrichMKEGG) and GSEA (gseKEGG & gseMKEGG). We can use bitr_kegg to convert ID for all these 4k species. To facilitate searching scientific name abbreviate used in the organism parameter of these functions, I implemented the search_kegg_organism function. We can search by kegg_code, scientific_name or common_name (which is not available for prokaryotes).

keyType parameter

With the ID conversion utilities built in clusterProfiler, I add a parameter keyType in enrichKEGG, enrichMKEGG, gseKEGG and gseMKEGG. Now we can use ID type that is not the primary ID in KEGG database.

setReadable

For GO analysis, we have a readable parameter to control whether traslating the IDs to human readable gene name. This parameter is not available for KEGG analysis. But we still have the ability to translate input gene IDs to gene name using setReadable function if and only if corresponding OrgDb object is available.