( ( ( The job ) ( of ( this gene ) ) ) ( ( is ( to ( produce ( ( ( a receptor ) ( -- ( ( ( a sort ) ( of ( molecular ( docking site ) ) ) ) -- ) ) ) ( for ( the ( brain ( chemical dopamine ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NN job)) (PP (IN of) (NP (DT this) (NN gene)))) (VP (VBZ is) (S (VP (TO to) (VP (VB produce) (NP (NP (NP (DT a) (NN receptor)) (PRN (: --) (NP (NP (DT a) (NN sort)) (PP (IN of) (NP (JJ molecular) (NN docking) (NN site)))) (: --))) (PP (IN for) (NP (DT the) (NN brain) (NN chemical) (NN dopamine)))))))) (. .)))
The job of this gene is to produce a receptor -- a sort of molecular docking site -- for the brain chemical dopamine.
(ROOT (S (NP (NNP Addiction)) (VP (VBZ affects) (NP (NP (DT the) (JJ dopamine) (NNS receptors)) (PP (IN within) (NP (DT the) (NN brain))))) (. .)))