Alignment.append_sequence() — add a sequence from one-letter codes

append_sequence(sequence, blank_single_chain=False, zero_width_break=False)

This builds a new sequence from the provided one-letter codes, and adds it to the end of the alignment. You can also use '-' and '/' characters in this sequence to add gaps and chain breaks.

By default, the newly created chains are labeled 'A', 'B', 'C' and so on. However, if only one chain is generated, and blank_single_chain is set True, it is given a blank chain ID.

Internally, a chain break is not a residue (it is essentially a signal to not construct a peptide bond between adjacent residues) and so has "zero width". However, the '/' character has a width of one just like a residue or a gap. To simplify alignment construction, if zero_width_break is False (the default), a gap is also added to the alignment when a chain break is encountered, so that other sequences will align. For example, after appending the two sequences AC/G and ETPW, G will align with W by default, or with P if zero_width_break is set to True.

Example: See Model.build_sequence() command.