#NEXUS
BEGIN TAXA;
      DIMENSIONS ntax=4;
      TAXLABELS  A B C D;
END;
BEGIN CHARACTERS;
      DIMENSIONS ntax=4 nchar=25
      FORMAT DATATYPE=protein;
MATRIX
  A     IKKGANLFKTRCAQCHTVEKDGGNI
  B     LKKGEKLFTTRCAQCHTLKEGEGNL
  C     STKGAKLFETRCKQCHTVENGGGHV
  D     LTKGAKLFTTRCAQCHTLEGDGGNI
;
END;
BEGIN TREES;
      TREE my_tree = (((A:1,B:1):1,D:0.5):1,C:2)root;
END;