The Gmubi promoter family was selected based on similarities in the protein-coding region of the gene. Gmubis1-9 encode perfect tetrameric repeats of the ubiquitin monomer. Gmubis1-7 are intron-containing while Gmubis8-9 do not contain introns. Gmubi10 is a promoter for a ubiquitin monomer. Extensive characterization of a slightly truncated form of Gmubi3 is described in:

CM Hernandez-Garcia, AP Martinelli, RA Bouchard, JJ Finer (2009) A soybean (Glycine max) polyubiquitin promoter gives strong constitutive expression in transgenic soybean. Plant Cell Rep 28:837-849