$/ = '//'; # input record separator
print join( " ", grep { s/^DE\s+// } split /\n/ ), "\n"
    while <DATA>;

##</code><code>##

AC2-(EC 2.7.00.1) (Adaptor-associated protein 1).
Serine/threonine-protein kinase (EC 2.7.99.1) (Tyrosine binding protein) (p35BP).
Serine/threonine-aaaaaa kinase (Tyrosine kinase 1) (Apoptosis-associated tyrosine kinase) (AATYK) (Brain binding protein) (p35BP).