ISSN:
1432-072X
Keywords:
Phototrophic bacteria
;
Rhodospirillaceae
;
Glutamine synthetase
;
Nitrogen metabolism
;
Nitrogen fixation
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract The phylogenetically related phototrophic bacteria Rhodospirillum tenue and Rhodocyclus purpureus modulate activity of their glutamine synthetases by adenylylation/deadenylylation. Evidence for covalent modification includes the inhibitory effect of Mg2+ on the activity of glutamine synthetase extracted from cells of either species grown on excess ammonia, and the lack of Mg2+ inhibition of activity of the enzyme isolated from N2-(R. tenue) or glutamine (R. purpureus)-grown cells. In addition, snake venom phosphodiesterase treatment of glutamine synthetase from either species grown on excess ammonia relieved Mg2+ inhibition of the enzyme (as measured via the γ-glutamyl transferase assay), and changed the cation specificity from Mn2+ to Mg2+ (in the biosynthetic assay).
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00447051
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