I am working with PICRUSt and I need a file mapping GreenGenes 13.8 OTUs (97% clustering) to IMG IDs. I know that PICRUSt provides a file in its tutorial, but this does not seem to be the correct version. Is there a way to find or generate these mapping files?
I know I am answering my own question, but this may be helpful for others. PICRUSt provides a set of precomputed files at https://picrust.github.io/picrust/picrust_precalculated_files.html. The KO file on this page is indexed by GreenGenes IDs, so it does not seem that any mapping is needed.