TY - JOUR
T1 - Posttranslational modification of nitrogenase
T2 - Differences between the purple bacterium Rhodospirillum rubrum and the cyanobacterium Anabaena variabilis
AU - DURNER, Jörg
AU - BÖHM, Ines
AU - HILZ, Helmuth
AU - BÖGER, Peter
PY - 1994/2
Y1 - 1994/2
N2 - In the photosynthetic bacteria Rhodospirillum rubrum and Rhodopseudomonas capsulatus post‐translational regulation of nitrogenase is due to ADP‐ribosylation of the Fe‐protein, the dinitrogenase reductase [Burris, R. H. (1991) J. Biol. Chem. 266, 9339–9342]. This mechanism has been assumed to be responsible for nitrogenase modification in a variety of organisms. In the present study, we examined whether ADP‐ribosylation holds true for the filamentous cyanobacterium Anabaena variabilis. Genes coding for the nitrogenase‐modifying enzymes dinitrogenase reductase‐activating glycohydrolase (DRAG) and dinitrogenase reductase ADP‐ribosyl transferase (DRAT) from R. rubrum have been subcloned and overexpressed in Escherichia coli. After isolation under anaerobic conditions, both proteins were functional as determined by in‐vitro assays using nitrogenase from R. rubrum as substrate. In contrast to the R. rubrum enzyme, nitrogenase from A. variabilis was not affected by DRAG or DRAT. Neither could inactive nitrogenase be restored by DRAG, nor nitrogenase activity suppressed by DRAT. Using specific antibodies against arginine‐bound ADP‐ribose [Meyer, T. & Hilz, H. (1986) Eur. J. Biochem. 155, 157–165], immunoblotting of the inactive, modified form of the Fe‐protein from R. rubrum but not that from A. variabilis showed a strong cross reaction. Furthermore, differently to R. rubrum no ADP‐ribosylated proteins could be detected at all, indicating the absence of this posttranslational modification in A. variabilis.
AB - In the photosynthetic bacteria Rhodospirillum rubrum and Rhodopseudomonas capsulatus post‐translational regulation of nitrogenase is due to ADP‐ribosylation of the Fe‐protein, the dinitrogenase reductase [Burris, R. H. (1991) J. Biol. Chem. 266, 9339–9342]. This mechanism has been assumed to be responsible for nitrogenase modification in a variety of organisms. In the present study, we examined whether ADP‐ribosylation holds true for the filamentous cyanobacterium Anabaena variabilis. Genes coding for the nitrogenase‐modifying enzymes dinitrogenase reductase‐activating glycohydrolase (DRAG) and dinitrogenase reductase ADP‐ribosyl transferase (DRAT) from R. rubrum have been subcloned and overexpressed in Escherichia coli. After isolation under anaerobic conditions, both proteins were functional as determined by in‐vitro assays using nitrogenase from R. rubrum as substrate. In contrast to the R. rubrum enzyme, nitrogenase from A. variabilis was not affected by DRAG or DRAT. Neither could inactive nitrogenase be restored by DRAG, nor nitrogenase activity suppressed by DRAT. Using specific antibodies against arginine‐bound ADP‐ribose [Meyer, T. & Hilz, H. (1986) Eur. J. Biochem. 155, 157–165], immunoblotting of the inactive, modified form of the Fe‐protein from R. rubrum but not that from A. variabilis showed a strong cross reaction. Furthermore, differently to R. rubrum no ADP‐ribosylated proteins could be detected at all, indicating the absence of this posttranslational modification in A. variabilis.
UR - http://www.scopus.com/inward/record.url?scp=0028040342&partnerID=8YFLogxK
U2 - 10.1111/j.1432-1033.1994.tb18606.x
DO - 10.1111/j.1432-1033.1994.tb18606.x
M3 - Article
C2 - 8119279
AN - SCOPUS:0028040342
SN - 0014-2956
VL - 220
SP - 125
EP - 130
JO - European Journal of Biochemistry
JF - European Journal of Biochemistry
IS - 1
ER -