Some commands (blastprotein, etc.) allow or require specifying a sequence from an “alignment” of one or more sequences open in ChimeraX.Command-line specification of a sequence is by alignment ID, as reported in the title bar of the Sequence Viewer window, and the name or index number of the sequence in the alignment, in the form:
alignment-ID:sequence-ID... enclosed in quotation marks if alignment-ID or sequence-ID includes spaces.
The index number can be a positive integer N for the Nth sequence in the alignment, or negative for the Nth-to-last sequence. For example,
super8.msf:-2specifies the next-to-last sequence in alignment super8.msf.
The alignment ID and colon (:) can be omitted if only one alignment is open or the sequence name given is unique across all alignments.
See also: command usage conventions