( ( ( Several proteins ) ( from ( ( prokaryotes and ) archaea ) ) ) ( ( ( are also ) ( modified ( by ( N-terminal acetylation ) ) ) ) . ) )
(ROOT (S (NP (NP (JJ Several) (NNS proteins)) (PP (IN from) (NP (NNS prokaryotes) (CC and) (NN archaea)))) (VP (VBP are) (ADVP (RB also)) (VP (VBN modified) (PP (IN by) (NP (JJ N-terminal) (NN acetylation))))) (. .)))
Several proteins from prokaryotes and archaea are also modified by N-terminal acetylation.
(ROOT (S (NP (NNS Bacteria) (CC and) (NNS archaea)) (VP (VBP are) (NP (NP (NNS examples)) (PP (IN of) (NP (NNS prokaryotes))))) (. .)))