Dear modeller team, I am using a variant of the align2d_mult.py script on your homepage. I want to use a multi-sequence alignment, align several template structures and the query sequence to it without changing the initial multi-sequence alignment. On the webpage it is mentioned that one can use align_block to fix a specific part of the alignment. Just to make sure - by using the script: #!/usr/bin/python from modeller import * log.verbose()#output=1, notes=1, warnings=1, errors=1, memory=0) env = environ() env.libs.topology.read(file='$(LIB)/top_heav.lib') # Read aligned sequences: aln = alignment(env) aln.append(file='../alignments/test.pir', align_codes='all') aln_block = len(aln) # Read aligned structures: aln.append(file='../templates/pdb_fit/alignment_test_structures.ali', align_codes='all') # Structure sensitive variable gap penalty sequence-sequence alignment: aln.salign(output='', max_gap_length=20, gap_function=False, # to use structure-dependent gap penalty alignment_type='PAIRWISE', align_block=aln_block, feature_weights=(1., 0., 0., 0., 0., 0.), overhang=0, gap_penalties_1d=(-450, 0), gap_penalties_2d=(0.35, 1.2, 0.9, 1.2, 0.6, 8.6, 1.2, 0., 0.), similarity_flag=True) aln.write(file='../alignments/modeller_multi.ali', alignment_format='PIR') aln.check() --------------------------- where "alignment_test_structures.ali" contains an alignment of potential template structures; is each of the sequence in "alignment_test_structures.ali" independently aligned to the alignment given in "test.pir" without changing the "test.pir" alignment? Thanks in advance! Kind regards, Simone