the data provide a strong indication that the e. coli aerobic respiratory chain contains two species of nadh dehydrogenases : ( i ) an enzyme ( nadh dh i ) that reacts with deamino-nadh or nadh whose turnover leads to generation of a h+ electrochemical gradient at a site between the primary dehydrogenase and ubiquinone and ( ii ) an enzyme ( nadh dh ii ) that reacts with nadh exclusively whose turnover does not lead to generation of a h+ electrochemical gradient between the primary dehydrogenase and ubiquinone 1 .
C0171406
nadh dh i
C0030016
dehydrogenase