Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.3.1.28 (chloramphenicol acetyltransferase)
 5,100 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

S-Adenosylmethionine decarboxylase (AdoMetDC) is a ubiquitous enzyme in eukaryotic cells and responds to a wide variety of stimuli affecting growth. To provide a framework for understanding the molecular basis of the mechanisms responsible for regulating the expression of this enzyme activity, we recently cloned and sequenced the rat gene for AdoMetDC. Now we have isolated another, slightly different AdoMetDC gene from a rat genomic library. Comparison of the two genes shows a high degree of conservation of sequence and structural organization. The two genes share the following characteristics: (1) both are approximately 16 kb in size, have identical exon/intron boundaries, and exhibit similar intron/exon structural organization; and (2) the nucleotide sequences are highly conserved in the coding regions and in many introns. Analysis of mouse-rat somatic cell hybrids has localized both rat genes to chromosome 20. The most interesting feature of these genes is that their 5' flanking regions are totally different. The promoter activities of the 5' regulatory regions were assessed by transient gene expression assays in Rat-2 cells after fusion to the chloramphenicol acetyltransferase gene. Transient transfections with the chimeric DNAs demonstrated that these fragments were able to function as efficient promoters, indicating that the diverging 5' regions of two AdoMetDC genes contain functional, but different, regulatory transcription elements.
 ...
PMID:Structures and chromosomal localizations of two rat genes encoding S-adenosylmethionine decarboxylase. 831 73

Mice homozygous for chromosomal deletions at or around the albino locus on chromosome 7 express reduced levels of a group of liver genes. Here, we report the isolation and characterization of cDNA and genomic clones encoding one of the affected genes, the mouse adult liver S-adenosylmethionine (AdoMet) synthetase. This enzyme catalyzes the synthesis of AdoMet, which functions in transmethylation and transsulfuration. Mouse AdoMet synthetase cDNA is 3232 base pairs (bp) in length and contains an open reading frame that encodes an enzymatically active polypeptide of 396 amino acids. The mouse AdoMet synthetase shares 98 and 96% amino acid sequence identity with the adult liver enzyme in the rat and human, respectively. AdoMet synthetases possess the consensus ATP-binding motif Gly-X-Gly-X-X-Gly and a putative ATP-binding Lys residue at conserved locations. As an initial step toward understanding the control of AdoMet synthetase gene expression, we characterized the complete transcription unit of this gene. The AdoMet synthetase gene spans approximately 18 kilobases and consists of nine exons ranging from 78 to 1920 bp. The transcription initiation site was demonstrated by rapid amplification of cDNA ends and confirmed by primer extension studies. A putative TATA box is located at -28 to -23 bp upstream of the transcription start site. The cis-acting DNA elements in the 5'-flanking region of the AdoMet synthetase gene that drive chloramphenicol acetyltransferase gene expression in mouse hepatocytes were identified by transient expression assays. The -365 to -2-bp DNA region upstream of the transcription start site of the AdoMet synthetase gene contains promoter elements, and the -518 to -366-bp DNA region might be involved in negative gene regulation.
 ...
PMID:Cloning and expression of murine S-adenosylmethionine synthetase. 831 64