Following the identification of murine beta-galactoside binding protein (mGBP) as an autocrine negative growth factor we have now isolated and characterized the genomic region spanning the mGBP gene and have determined the 5' end of the transcript by primer extension, S1 mapping and mRNA sequence. The gene is found to be contained within 4 kilobases and composed of four exons of 79, 80, 171 and 197 nucleotides separated by three introns of 1200, 1600 and 193 nucleotides. The DNA region upstream of the 5' end of the transcript contains canonical sequences for eukaryotic promoter elements including CAT and TATA boxes and several DNA motifs for potential transcription regulation. The gene is differentially expressed in a variety of normal tissues.