Johansson B C, Gest H
J Bacteriol. 1976 Nov;128(2):683-8. doi: 10.1128/jb.128.2.683-688.1976.
The photosynthetic bacterium Rhodopseudomonas capsulata lacks glutamate dehydrogenase and normally uses the glutamine synthetase/glutamate synthase sequence of reactions for assimilation of N2 and ammonia. The glutamine synthetase in cell-free extracts of the organism is completely sedimented by centrifugation at 140,000 X g for 2 h, is inhibited by L-alanine but not by adenosine 5'-monophosphate, and exhibits two apparent Km values for ammonia (ca. 13 muM and 1 mM).
光合细菌荚膜红假单胞菌缺乏谷氨酸脱氢酶,通常利用谷氨酰胺合成酶/谷氨酸合酶反应序列来同化氮气和氨。该生物体无细胞提取物中的谷氨酰胺合成酶在140,000×g离心2小时后完全沉淀,受L-丙氨酸抑制但不受5'-单磷酸腺苷抑制,并且对氨表现出两个表观Km值(约13μM和1mM)。