Cloning and sequencing of cDNA of bovine N-acetylglucosamine (beta 1-4)galactosyltransferase.
Galactosyltransferases constitute a family of enzymes, each member of which transfers galactose from UDPgalactose to a specific acceptor molecule, generating a specific galactose-acceptor linkage. Two synthetic oligonucleotides, 27mer and 21mer, were synthesized, based on the amino acid sequences of two peptides derived from bovine milk N-acetylglucosaminide (beta 1-4)galactosyltransferase (EC 2.4.1.90), and used as hybridization probes to isolate cDNA clones for galactosyltransferase from a bovine mammary gland cDNA library. One of the plasmids, designated pLbGT-1, contains an insert of about 3.7 kilobases that hybridizes to both of the probes and encodes the amino acid sequences of five peptides obtained from bovine milk (beta 1-4)galactosyltransferase. A second plasmid, designated pLbGT-2, contains an insert of about 4.1 kilobases that hybridizes to only the 27mer and that encodes a polypeptide containing the sequence of the carboxyl-terminal 120 residues identical to the peptide encoded by pLbGT-1; the rest of the protein sequence, however, does not contain known sequences from bovine galactosyltransferase. The two cDNAs contain a 3'-untranslated region of about 2.7 kilobases that includes two copies of the Alu-equivalent sequences. pLbGT-1 and pLbGT-2 hybridize to mRNAs of various sizes obtained from the bovine and rat mammary gland and the human mammary tumor cell line MCF-7, with the longest mRNA from each species being around 4.5 kilobases. The results show that pLbGT-1 is a cDNA clone for bovine (beta 1-4)galactosyltransferase, and pLbGT-2 encodes a protein that is structurally and may be functionally related to transferases.
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002417:Cattle; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D004262:DNA Restriction Enzymes / Q000235:genetics; D007788:Lactose Synthase / Q000235:genetics*; D009237:N-Acetyllactosamine Synthase / Q000235:genetics*; D009693:Nucleic Acid Hybridization; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid
D012333:RNA, Messenger; D004247:DNA; D007788:Lactose Synthase; D009237:N-Acetyllactosamine Synthase; D004262:DNA Restriction Enzymes