(S (S (NP (BASENP (DT The) (NN three) (NNS genes)) (COMMA ,) (VP (VBN called) (S (NP (NP (BASENP (NN gag)) (COMMA ,) (BASENP (NN pol))) (CC and) (BASENP (NN env)))))) (VP (VBP contain) (NP (BASENP (NN information)) (VP (VBN needed) (S (VP (TO to) (VP (VB make) (NP (BASENP (DT the) (JJ structural) (NNS proteins)) (PP (IN for) (NP (BASENP (DT the) (NN capsid)) (COMMA ,) (NP (BASENP (DT the) (QT (DQL ``) (NN shell) (DQR ''))) (PP (IN of) (BASENP (DT the) (NN HIV) (NN viron)))))))))))))) (PERIOD .))