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B6db activities:
Description Nicotianamine aminotransferase
Alternative names NAAT;
Catalyzed reaction Nicotianamine + 2-oxoglutarate = 3"-deamino-3"-oxonicotianamine + L-glutamate
Cofactor Pyridoxal-phosphate.
Comments 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.
Available at least two characterized sequences (both from Hordeum vulgare).
This enzyme activity is apparently missing in plants other than graminaceous.
Organisms -Plants

Family (0)
Links Enzyme (activities)
BRENDA (activities)
KEGG (pathways)
PLPMDB (PLP mutants)
 Beasley JT, Bonneau JP, Johnson AAT (2017) Characterisation of the nicotianamine aminotransferase and deoxymugineic acid synthase genes essential to Strategy II iron uptake in bread wheat (Triticum aestivum L.) PLoS One 12 e0177061.

 Cheng L, Wang F, Shou H, Huang F, Zheng L, He F, Li J, Zhao FJ, Ueno D, Ma JF, Wu P. (2007) Mutation in Nicotianamine Aminotransferase Stimulated the Fe(II) Acquisition System and Led to Iron Accumulation in Rice Plant Physiol 145 1647-57.

 Takahashi, M., Yamaguchi, H., Nakanishi, H., Shioiri, T., Nishizawa, N.K., Mori, S. (1999) Cloning two genes for nicotianamine aminotransferase, a critical enzyme in iron acquisition (Strategy II) in graminaceous plants Plant Physiol 121 947-956.

Articles on
last changed 2009/07/07 15:42

B6db activities