Evidence for adenylylation/deadenylylation control of the glutamine synthetases of Rhodospirillum tenue and Rhodocyclus purpureus |
| |
Authors: | Richard A Masters Michael T Madigan |
| |
Affiliation: | (1) Department of Microbiology, Southern Illinois University, 62901 Carbondale, IL, USA |
| |
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 -glutamyl transferase assay), and changed the cation specificity from Mn2+ to Mg2+ (in the biosynthetic assay). |
| |
Keywords: | Phototrophic bacteria Rhodospirillaceae Glutamine synthetase Nitrogen metabolism Nitrogen fixation |
本文献已被 SpringerLink 等数据库收录! |