Reaction: nicotianamine + 2-oxoglutarate = 3"-deamino-3"-oxonicotianamine + L-glutamate
For diagram click here.
Other name(s): NAAT; NAAT-I; NAAT-II; NAAT-III; nicotianamine transaminase
Systematic name: nicotianamine:2-oxoglutarate aminotransferase
Comments: A pyridoxal-phosphate protein. This enzyme is produced by grasses. They secrete both the nicotianamine and the transaminated product into the soil around them. Both compounds chelate iron(II) and iron(III); these chelators, called mugineic acid family phytosiderophores, are taken up by the grass, which is thereby supplied with iron.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 154907-64-9
References:
1. Kanazawa, K., Higuchi, K., Nishizawa, N.-K., Fushiya, S., Chino, M. and Mori, S. Nicotianamine aminotransferase activities are correlated with the phytosiderophore secretions under Fe-deficient conditions in Gramineae. J. Exp. Bot. 45 (1994) 1903-1906.
2. Takahashi, M., Yamaguchi, H., Nakanishi, H., Shioiri, T., Nishizawa, N.K. and Mori, S. Cloning two genes for nicotianamine aminotransferase, a critical enzyme in iron acquisition (Strategy II) in graminaceous plants. Plant Physiol. 121 (1999) 947-956. [PMID: 10557244]
3. Schaaf, G., Ludewig, U., Erenoglu, B.E., Mori, S., Kitahara, T. and von Wirén, N. ZmYS1 functions as a proton-coupled symporter for phytosideorophore- and nicotianamine-chelated metals. J. Biol. Chem. 279 (2004) 9091-9096. [PMID: 14699112]