Biomaterial Database

Nucleotide sequence of the Escherichia coli gene for lipid A disaccharide synthase. 1987

D N Crowell, and W S Reznikoff, and C R Raetz

Department of Biochemistry, College of Agricultural and Life Sciences, University of Wisconsin-Madison 53706.

The lpxB gene of Escherichia coli, believed to be the structural gene for lipid A disaccharide synthase, is located in the min 4 region of the chromosome. It is adjacent to and clockwise of the lpxA gene, which is thought to encode UDP-N-acetylglucosamine acyltransferase. Preliminary evidence suggests that lpxA and lpxB are cotranscribed in the clockwise direction and thus constitute part of a previously unknown operon (D. N. Crowell, M. S. Anderson, and C. R. H. Raetz, J. Bacteriol. 168:152-159, 1986). We now report the complete nucleotide sequence of a 1,522-base-pair PvuII-HincII fragment known to carry the lpxB gene. This sequence contained an open reading frame of 1,149 base pairs, in agreement with the predicted size, location, and orientation of lpxB. There was a second open reading frame 5' to, and in the same orientation as, lpxB that corresponded to lpxA. The ochre codon terminating lpxA was shown to overlap the methionine codon identified as the initiation codon for lpxB, suggesting that these genes are cotranscribed and translationally coupled. A third open reading frame was also shown to begin at the 3' end of lpxB with analogous overlap between the opal codon terminating lpxB and the methionine codon that putatively initiates translation downstream of lpxB in the clockwise direction. These results argue that at least three genes constitute a translationally coupled operon in the min 4 region of the E. coli chromosome. The accompanying paper by Tomasiewicz and McHenry (J. Bacteriol. 169:5735-5744, 1987) presents 4.35 kilobases of DNA sequence, beginning at the 3' end of lpxB, and argues that dnaE and several other open reading frames may be members of this operon.

UI	MeSH Term	Description	Entries
D008050	Lipid A	Lipid A is the biologically active component of lipopolysaccharides. It shows strong endotoxic activity and exhibits immunogenic properties.
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D009876	Operon	In bacteria, a group of metabolically related genes, with a common promoter, whose transcription into a single polycistronic MESSENGER RNA is under the control of an OPERATOR REGION.	Operons
D002621	Chemistry	A basic science concerned with the composition, structure, and properties of matter; and the reactions that occur between substances and the associated energy exchange.
D003001	Cloning, Molecular	The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.	Molecular Cloning
D003062	Codon	A set of three nucleotides in a protein coding sequence that specifies individual amino acids or a termination signal (CODON, TERMINATOR). Most codons are universal, but some organisms do not produce the transfer RNAs (RNA, TRANSFER) complementary to all codons. These codons are referred to as unassigned codons (CODONS, NONSENSE).	Codon, Sense,Sense Codon,Codons,Codons, Sense,Sense Codons
D004262	DNA Restriction Enzymes	Enzymes that are part of the restriction-modification systems. They catalyze the endonucleolytic cleavage of DNA sequences which lack the species-specific methylation pattern in the host cell's DNA. Cleavage yields random or specific double-stranded fragments with terminal 5'-phosphates. The function of restriction enzymes is to destroy any foreign DNA that invades the host cell. Most have been studied in bacterial systems, but a few have been found in eukaryotic organisms. They are also used as tools for the systematic dissection and mapping of chromosomes, in the determination of base sequences of DNAs, and have made it possible to splice and recombine genes from one organism into the genome of another. EC 3.21.1.	Restriction Endonucleases,DNA Restriction Enzyme,Restriction Endonuclease,Endonuclease, Restriction,Endonucleases, Restriction,Enzymes, DNA Restriction,Restriction Enzyme, DNA,Restriction Enzymes, DNA
D004269	DNA, Bacterial	Deoxyribonucleic acid that makes up the genetic material of bacteria.	Bacterial DNA
D004926	Escherichia coli	A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.	Alkalescens-Dispar Group,Bacillus coli,Bacterium coli,Bacterium coli commune,Diffusely Adherent Escherichia coli,E coli,EAggEC,Enteroaggregative Escherichia coli,Enterococcus coli,Diffusely Adherent E. coli,Enteroaggregative E. coli,Enteroinvasive E. coli,Enteroinvasive Escherichia coli
D005796	Genes	A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms.	Cistron,Gene,Genetic Materials,Cistrons,Genetic Material,Material, Genetic,Materials, Genetic