segment {<segment-statement>} end
<segment-statement> :==
name=<segid>
Segid of newly created structure. default=" "
separate-by-segid=<logical>
When reading the sequence from a file, if a new segid is encountered
finish the chain and start a new one.
convert-chainid-to-segid=<logical>
When reading a sequence from a file, take the segid from the chainid
column if it is non-blank.
coordinates {<pdb-atom-record>} end
Read sequence from PDB file.
Several link, first and last statements may be given equality
has priority before wildcard matching. The more specific assignments
must come first.