Discrepancies between taxonomic assignments made by BLASTN and STAP.

Bacterial sequences for which the assignments made by BLASTN differed from those made by STAP were identified, and the level of the Hugenholtz annotation for each was noted. Accuracy was scored based on comparisons with the Hugenholtz annotation. Those few cases where the BLASTN results matched the annotations but the STAP results did not were always found to be due to incorrect annotation in the Greengenes database for the sequence's closest neighbor in the tree. Sequences whose position in the STAP-generated tree was between neighboring groups were classified as “unresolved.”