The nuclear genome of soybean (Glycine max L.) contains a family of four tuf genes coding for the chloroplast translation elongation factor EF-Tu. Genomic and cDNA sequencing reveal that the four tuf genes belong to two subfamilies (type A and type B). Tuf genes are highly expressed in green organs (leaves and stems) while tuf genes are poorly expressed in leaves and stems. Both types of genes are about equally expressed in roots albeit at a low level. The 5' flanking regions of tufA1 and B1 are tested for promoter activities (GUS) in transformed green tobacco. The tufA1 promoter is much stronger than the B1 promoter. Promoter deletion studies with tufA1-derived constructs allowed identification of a DNA segment essential for gene transcription.