title: ATP-dependent and NAD-dependent modification of glutamine synthetase from Rhodospirillum rubrum in vitro.
abstract: Glutamine synthetase from the photosynthetic bacterium Rhodospirillum rubrum is the target of both ATP- and NAD-dependent modification. Incubation of R. rubrum cell supernatant with [alpha-32P]NAD results in the labeling of glutamine synthetase and two other unidentified proteins. Dinitrogenase reductase ADP-ribosyltransferase does not appear to be responsible for the modification of glutamine synthetase or the unidentified proteins. The [alpha-32P]ATP- and [alpha-32P] NAD-dependent modifications of R. rubrum glutamine synthetase appear to be exclusive and the two forms of modified glutamine synthetase are separable on two-dimensional gels. Loss of enzymatic activity by glutamine synthetase did not correlate with [alpha-32P]NAD labeling. This is in contrast to inactivation by nonphysiological ADP-ribosylation of other glutamine synthetases by an NAD:arginine ADP-ribosyltransferase from turkey erythrocytes (Moss, J., Watkins, P.A., Stanley, S.J., Purnell, M.R., and Kidwell, W.R. (1984) J. Biol. Chem. 259, 5100-5104). A 32P-labeled protein spot comigrates with the NAD-treated glutamine synthetase spot when glutamine synthetase purified from H3 32PO4-grown cells is analyzed on two-dimensional gels. The adenylylation site of R. rubrum glutamine synthetase has been determined to be Leu-(Asp)-Tyr-Leu-Pro-Pro-Glu-Glu-Leu-Met; the tyrosine residue is the site of modification.
authors.affiliation: Department of Biochemistry, University of Wisconsin, Madison 53706.
authors.forename: D L
authors.initials: DL
authors.lastname: Woehle
authors.forename: B A
authors.initials: BA
authors.lastname: Lueddecke
authors.forename: P W
authors.initials: PW
authors.lastname: Ludden
mesh_terms: D000246:Adenosine Diphosphate Ribose / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism*; D000595:Amino Acid Sequence; D001665:Binding Sites; D015180:Electrophoresis, Gel, Two-Dimensional; D004591:Electrophoresis, Polyacrylamide Gel; D005974:Glutamate-Ammonia Ligase / Q000302:isolation & purification / Q000378:metabolism*; D005971:Glutamates / Q000378:metabolism; D018698:Glutamic Acid; D007106:Immune Sera; D015151:Immunoblotting; D007700:Kinetics; D008293:Malates / Q000378:metabolism; D008969:Molecular Sequence Data; D009243:NAD / Q000378:metabolism*; D010446:Peptide Fragments / Q000302:isolation & purification; D010761:Phosphorus Radioisotopes; D012247:Rhodospirillum rubrum / Q000201:enzymology* / Q000254:growth & development
chemical_list: D005971:Glutamates; D007106:Immune Sera; D008293:Malates; D010446:Peptide Fragments; D010761:Phosphorus Radioisotopes; D009243:NAD; D000246:Adenosine Diphosphate Ribose; D018698:Glutamic Acid; C030298:malic acid; D000255:Adenosine Triphosphate; D005974:Glutamate-Ammonia Ligase