Molecular cloning, structural characterization and chromosomal localization of human lipoyltransferase gene.
Lipoyltransferase catalyzes the transfer of the lipoyl group from lipoyl-AMP to the lysine residue of the lipoate-dependent enzymes. We isolated human lipoyltransferase cDNA and genomic DNA. The cDNA insert contained a 1119-base pair open reading frame encoding a precursor peptide of 373 amino acids. Predicted amino acid sequence of the protein shares 88 and 31% identity with bovine lipoyltransferase and Escherichia coli lipoate-protein ligase A, respectively. Northern blot analyses of poly(A)+ RNA indicated a major species of about 1.5 kb. mRNA levels of lipoyltransferase were highest in skeletal muscle and heart, showing good correlation with those of dihydrolipoamide acyltransferase subunits of pyruvate, 2-oxoglutarate and branched-chain 2-oxo acid dehydrogenase complexes and H-protein of the glycine cleavage system which accept lipoic acid as a prosthetic group. The human lipoyltransferase gene is a single copy gene composed of four exons and three introns spanning approximately 8 kb of genomic DNA. Some alternatively spliced mRNA species were found by 5'-RACE analysis, and the most abundant species lacks the third exon. The human lipoyltransferase gene was localized to chromosome band 2q11.2 by fluorescence in situ hybridization.
Fujiwara
K
K
Institute for Enzyme Research, University of Tokushima, Japan.
Suzuki
M
M
Okumachi
Y
Y
Okamura-Ikeda
K
K
Fujiwara
T
T
Takahashi
E
E
Motokawa
Y
Y
D000217:Acyltransferases / Q000235:genetics*; D000595:Amino Acid Sequence; D001483:Base Sequence; D015152:Blotting, Northern; D002874:Chromosome Mapping; D002889:Chromosomes, Human, Pair 2; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000032:analysis; D015894:Genome, Human; D006801:Humans; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000378:metabolism; D014018:Tissue Distribution
D018076:DNA, Complementary; D012333:RNA, Messenger; D000217:Acyltransferases