nodulin MtN21 family protein. similar to nodulin MtN21 family protein [Arabidopsis thaliana] (TAIR:AT4G08300.1); similar to nodulin family protein [Gossypium hirsutum] (GB:ABS52574.1); contains InterPro domain Protein of unknown function DUF6, transmembrane; (InterPro:IPR000620)