I'm interested in taxonomic classification of sequences. RDP is fine if you want the genus-level but sub-genus classification is harder (and a whole subject of its own). That said, RDP has a tool called seqmatch that gives you a list of candidate templates that match your query. I don't really like the output of Seqmatch though and I'm trying to figure out how to get MOTHUR to do something similar. The align.seqs command is probably almost doing what I need, selecting the best template and scoring the alignment, but I have no idea if the best template was really the best or just one of several equally good templates. Furthermore, I sometimes have low quality positions in my sequences that I'd like to mask (with Ns for instance) so they do not contribute to the scoring. Has anyone used MOTHUR in such a way?