A model of nitrogen flow by malonamate in Rhizobium japonicum-soybean symbiosis.
Two types of novel malonamidases were found in soybean nodules. One (E1) catalyzes the formation of malonamate from malonate and its hydrolysis to ammonia, whereas the other (E2) acts mainly on the hydrolysis of malonamate. E1 and E2 were found in bacteroids, but only E2 was found in the plant cytosol of the nodule. The substrate requirements of E1 and E2 were highly specific for malonate and malonamate, respectively. From these and other results reported previously, we propose that malonamate plays an important role as a nitrogen carrier in the Rhizobium legume symbiosis.
Kim
Y S
YS
Department of Biochemistry, Yonsei University, Seoul, Korea.
Chae
H Z
HZ
D000581:Amidohydrolases / Q000302:isolation & purification / Q000378:metabolism*; D000641:Ammonia / Q000378:metabolism; D001426:Bacterial Proteins; D002846:Chromatography, Affinity; D002852:Chromatography, Ion Exchange; D003600:Cytosol / Q000378:metabolism; D008314:Malonates / Q000378:metabolism*; D008954:Models, Biological; D009584:Nitrogen / Q000378:metabolism*; D012231:Rhizobium / Q000378:metabolism*; D013025:Glycine max / Q000378:metabolism*; D013559:Symbiosis
D001426:Bacterial Proteins; D008314:Malonates; C013098:malonamic acid; D000641:Ammonia; D000581:Amidohydrolases; C064615:malonamidase E2 protein, Bradyrhizobium japonicum; D009584:Nitrogen