Sequence alignment between 1a48(A) and UniProt seq P27616 (PUR7_YEAST):

P27616 (PUR7_YEAST): Phosphoribosylaminoimidazole-succinocarboxamide synthase from Saccharomyces cerevisiae (strain ATCC 204508 / S288c)
                 10        20        30        40        50        60        70        80        90       100       110       120       130       140       150       160       170       180       190       200       210       220       230       240       250       260       270       280       290       300      
         ---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+------
UniProt: MSITKTELDGILPLVARGKVRDIYEVDAGTLLFVATDRISAYDVIMENSIPEKGILLTKLSEFWFKFLSNDVRNHLVDIAPGKTIFDYLPAKLSEPKYKTQLEDRSLLVHKHKLIPLEVIVRGYITGSAWKEYVKTGTVHGLKQPQGLKESQEFPEPIFTPSTKAEQGEHDENISPAQAAELVGEDLSRRVAELAVKLYSKCKDYAKEKGIIIADTKFEFGIDEKTNEIILVDEVLTPDSSRFWNGASYKVGESQDSYDKQFLRDWLTANKLNGVNGVKMPQDIVDRTRAKYIEAYETLTGSKWSH
         ...................................................................................................................................................................XXXXXXX........................................................................................................................................
PDB seq: -SITKTELDGILPLVARGKVRDIYEVDAGTLLFVATDRISAYDVIMENSIPEKGILLTKLSEFWFKFLSNDVRNHLVDIAPGKTIFDYLPAKLSEPKYKTQLEDRSLLVHKHKLIPLEVIVRGYITGSAWKEYVKTGTVHGLKQPQGLKESQEFPEPIFTPST-------DENISPAQAAELVGEDLSRRVAELAVKLYSKCKDYAKEKGIIIADTKFEFGIDEKTNEIILVDEVLTPDSSRFWNGASYKVGESQDSYDKQFLRDWLTANKLNGVNGVKMPQDIVDRTRAKYIEAYETLTGSKWSH
          --------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---       ---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+------
                 10        20        30        40        50        60        70        80        90       100       110       120       130       140       150       160                 180       190       200       210       220       230       240       250       260       270       280       290       300