Prolamin_like (in which DUF784 and DUF1278 have been merged) is found to be expressed in the plant embryo sac and to be regulated by the Myb98 transcription factor. Computational analysis has revealed that members are homologous to the plant prolamin superfamily (Protease inhibitor-seed storage-LTP family, Pfam:PF00234) [1]. In contrast to typical prolamin members that have eight conserved Cys residues forming four pairs of disulfide bonds, this domain contains only six conserved Cys residues that may form three pairs of disulfide bonds. The domain may have a potential function in lipid transfer or protection during plant embryo sac development and reproduction [2].

1: Homology between DUF784, DUF1278 domains and the plant prolamin superfamily typifies evolutionary changes of disulfide bonding patterns. Zhang D; Cell Cycle. 2009;8:3428-3430. PMID:19806031

2: Genome-wide expression profiling of the Arabidopsis female gametophyte identifies families of small, secreted proteins. Jones-Rhoades MW, Borevitz JO, Preuss D; PLoS Genet. 2007;3:1848-1861. PMID:17937500