[Isolation and cloning of human beta 1, 4-galactosyltransferase III gene]

Using the conservative nucleotide sequences encoding the catalytic domain of the beta-1, 4-GalT genes in human, bovine, mouse, chick and snail as probes to search the NCBI GenBank EST database, several ESTs with high homology were obtained. Primers were designed in the flanking sequence of EST contig. Using the PCR product amplified in human placenta cDNA library as probe to perform "walking" hybridization with human placenta cDNA library, a cDNA fragment with the length of 1,907 bp was cloned. It contained an open reading frame (ORF) with the length of 1,179 bp, which encodes 393 amino acid residues. The deduced amino acid sequence of this gene shares 43.8% identity to the human beta-1, 4-GalTI and 60.9% in the catalytic domain especially. The expression mapping showed that it was expressed in human most tissues with a single 2.4 kb transcript, but the relative expression level of the transcript are vary. While this gene was mapped on chromosome 1 using the cDNA hybridization with human/rodent hybrid cell line DNA Southern blot panel.