I have a question about 1st part of basic modeller tutorial. As I understood the profile.build() method could be useful for scanning seq_database_file='pdb_95.pir' file where the sequences of the possible templates with known structures are provided against target  which are defined further by means of aln.append(file='TvLDH.ali'). Does it possible to use blast search method within the modeller script to create such seq_database_file pir file firstly which will consist of all found pdb's structures with the defined threshold sequence against target sequence (e.g not less as 50% of sequence homology)?