An L‐methionine—D,L‐sulfoximine‐resistant mutant of the cyanobacterium Nostoc muscorum showing inhibitor‐resistant γ‐glutamyl‐transferase, defective glutamine synthetase and producing extracellular ammonia during N2 fixation

FEBS Letters

Singh, R.K.¹  Singh, H.N.¹  Sharma, R.¹ 

[1] School of Life Sciences, University of Hyderabad, Hyderabad-500 134, India

关键词: Glutamine synthetase;    γ-Glutamyl-transferase;    Cyanobacterium;    L-Methionine—D;    L-sulfoximine;    Nitrogen fixation;    Ammonia excretion;   

DOI  :  10.1016/0014-5793(83)80867-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The role of γ-glutamyl-transferase in regulation of N₂-fixation and ammonia assimilation in Nostoc muscorum was examined by isolating mutants in which the enzyme was resistant to L-methionine—D,L-sulfoximine. Mutant and wild-type were compared with respect to nitrogenase activity, extracellular production of nitrogenase-catalysed ammonia, γ-glutamyl-transferase activity and growth in N₂ and glutamine media. While the production of inhibitor-resistant enzyme with defective γ-glutamyl-transferase activity fully explains the inhibitor-resistant growth phenotype, the present results also suggest close metabolic linkage between γ-glutamyl transferase, nitrogenase and assimilation and extracellular production of N₂-derived ammonia.

【 授权许可】

Unknown