I thought the same thing, but then concluded that the data is probably read in from a file rather than hardcoded into a program and was only posted that way for the purposes of asking the question.

If I really had to embed such long lines of text into a script, I'd probably use something like

@array = (
    '>143B_HUMAN (P31946) 14-3-3 protein beta/alpha '
  . '(Protein kinase C inhibitor protein-1) (KCIP-1) (Protein 1054) '
  . 'TMDKSELVQKAKLAEQAERYDDMAAAMKAVTEQGHELSNEERNLLSVAYKNVVGARRSSWR'
  . 'VISSIEQKTERNEKKQQMGKEYREKIEAELQDICNDVLELLDKYLIPNATQPESKVFYLKM'
  . 'KGDYFRYLSEVASGDNKQTTVSNSQQAYQEAFEISKKEMQPTHPIRLGLALNFSVFYYEIL'
  . 'NSPEKACSLAKTAFDEAIAELDTLNEESYKDSTLIMQLLRDNLTLWTSENQGDEGDAGEGEN', 
  # ...
);
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