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Nicotinamide is a specific inhibitor of dark‐operative protochlorophyllide oxidoreductase, a nitrogenase‐like enzyme, from Rhodobacter capsulatus
Author(s) -
Nomata Jiro,
Kondo Toru,
Itoh Shigeru,
Fujita Yuichi
Publication year - 2013
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2013.07.054
Subject(s) - protochlorophyllide , oxidoreductase , rhodobacter , nitrogenase , biochemistry , chemistry , electron transfer , enzyme , nicotinamide , stereochemistry , photochemistry , organic chemistry , nitrogen fixation , mutant , nitrogen , gene
Dark‐operative protochlorophyllide oxidoreductase (DPOR) is a nitrogenase‐like enzyme consisting of two components, L‐protein as a reductase component and NB‐protein as a catalytic component. Elucidation of the crystal structures of NB‐protein (Muraki et al., Nature 2010, 465: 110–114) has enabled us to study its reaction mechanism in combination with biochemical analysis. Here we demonstrate that nicotinamide (NA) inhibits DPOR activity by blocking the electron transfer from L‐protein to NB‐protein. A reaction scheme of DPOR, in which the binding of protochlorophyllide (Pchlide) to the NB‐protein precedes the electron transfer from the L‐protein, is proposed based on the NA effects.