Sequence alignment between 2ith(A) and UniProt seq P15093 (DYRA_HALVD):

P15093 (DYRA_HALVD): Dihydrofolate reductase HdrA from Haloferax volcanii (strain ATCC 29605 / DSM 3757 / JCM 8879 / NBRC 14742 / NCIMB 2012 / VKM B-1768 / DS2) 
                 10        20        30        40        50        60        70        80        90       100       110       120       130       140       150       160  
         ---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+--
UniProt: MELVSVAALAENRVIGRDGELPWPSIPADKKQYRSRIADDPVVLGRTTFESMRDDLPGSAQIVMSRSERSFSVDTAHRAASVEEAVDIAASLDAETAYVIGGAAIYALFQPHLDRMVLSRVPGEYEGDTYYPEWDAAEWELDAETDHEGFTLQEWVRSASSR
         ....................................X.............................................................................................................................
PDB seq: MELVSVAALAENRVIGRDGELPWPSIPADKKQYRSRVADDPVVLGRTTFESMRDDLPGSAQIVMSRSERSFSVDTAHRAASVEEAVDIAASLDAETAYVIGGAAIYALFQPHLDRMVLSRVPGEYEGDTYYPEWDAAEWELDAETDHEGFTLQEWVRSASSR
         ---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+--
                 10        20        30        40        50        60        70        80        90       100       110       120       130       140       150       160