Sequence alignment between 1f9h(A) and UniProt seq P26281 (HPPK_ECOLI):

P26281 (HPPK_ECOLI): 2-amino-4-hydroxy-6-hydroxymethyldihydropteridine pyrophosphokinase from Escherichia coli (strain K12)
                 10        20        30        40        50        60        70        80        90       100       110       120       130       140       150         
         ---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------
UniProt: MTVAYIAIGSNLASPLEQVNAALKALGDIPESHILTVSSFYRTPPLGPQDQPDYLNAAVALETSLAPEELLNHTQRIELQQGRVRKAERWGPRTLDLDIMLFGNEVINTERLTVPHYDMKNRGFMLWPLFEIAPELVFPDGEMLRQILHTRAFDKLNKW
         ............................................................................................X..................................................................
PDB seq: -TVAYIAIGSNLASPLEQVNAALKALGDIPESHILTVSSFYRTPPLGPQDQPDYLNAAVALETSLAPEELLNHTQRIELQQGRVRKAERWGPATLDLDIMLFGNEVINTERLTVPHYDMKNRGFMLWPLFEIAPELVFPDGEMLRQILHTRAFDKLNKW
          ---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+--------
                  10        20        30        40        50        60        70        80        90       100       110       120       130       140       150