( ( ( ( ( Two ( additional proteins ) ) , ) ( ( titin and ) nebulin ) ) , ) ( also ( ( contribute ( to ( sarcomere ( ( structure and ) stability ) ) ) ) . ) ) )
(ROOT (S (NP (NP (CD Two) (JJ additional) (NNS proteins)) (, ,) (NP (NN titin) (CC and) (NN nebulin)) (, ,)) (ADVP (RB also)) (VP (VBP contribute) (S (VP (TO to) (VP (VB sarcomere) (NP (NN structure) (CC and) (NN stability)))))) (. .)))
Two additional proteins, titin and nebulin , also contribute to sarcomere structure and stability.
(ROOT (S (NP (DT The) (ADJP (JJS largest) (VBN known)) (NNS proteins)) (VP (VBP are) (ADJP (JJ titins))) (. .)))