Biomaterial Database

Nucleotide sequence of the hemC locus encoding porphobilinogen deaminase of Escherichia coli K12. 1986

S D Thomas, and P M Jordan

Porphobilinogen deaminase, the product of the hemC locus in Escherichia coli K12, catalyses the tetrapolymerisation of porphobilinogen (PBG) into the hydroxymethylbilane, preuroporphyrinogen. The hemC locus has been subcloned from the Clarke and Carbon plasmid pLC41-4. The sequence of the hemC structural gene and flanking DNA was determined by the dideoxy chain termination method of Sanger. The structural gene for hemC is located within a 942bp sequence encoding the monomeric PBG deaminase, molecular weight 33,857. The extent of the coding region was confirmed by sequencing the N-terminus of the purified enzyme and by determination of the molecular weight. The hemC locus is closely linked to the cyaA locus, the genes being transcribed in a divergent manner. Upstream of the hemC coding region, a possible promoter and three repeated GGATG sequences were identified. This is the first report of a complete DNA sequence for a structural gene specifying an enzyme of the heme biosynthetic pathway in prokaryotes.

UI	MeSH Term	Description	Entries
D011163	Hydroxymethylbilane Synthase	An enzyme that catalyzes the tetrapolymerization of the monopyrrole PORPHOBILINOGEN into the hydroxymethylbilane preuroporphyrinogen (UROPORPHYRINOGENS) in several discrete steps. It is the third enzyme in the 8-enzyme biosynthetic pathway of HEME. In humans, deficiency in this enzyme encoded by HMBS (or PBGD) gene results in a form of neurological porphyria (PORPHYRIA, ACUTE INTERMITTENT). This enzyme was formerly listed as EC 4.3.1.8	Porphobilinogen Ammonia-Lyase,Porphobilinogen Deaminase,Uroporphyrinogen I Synthase,Hydroxymethylbilane Synthetase,Pre-uroporphyrinogen Synthetase,Preuroporphyrinogen Synthetase,Ammonia-Lyase, Porphobilinogen,Deaminase, Porphobilinogen,Porphobilinogen Ammonia Lyase,Pre uroporphyrinogen Synthetase,Synthase, Hydroxymethylbilane,Synthase, Uroporphyrinogen I,Synthetase, Hydroxymethylbilane,Synthetase, Pre-uroporphyrinogen,Synthetase, Preuroporphyrinogen
D011401	Promoter Regions, Genetic	DNA sequences which are recognized (directly or indirectly) and bound by a DNA-dependent RNA polymerase during the initiation of transcription. Highly conserved sequences within the promoter include the Pribnow box in bacteria and the TATA BOX in eukaryotes.	rRNA Promoter,Early Promoters, Genetic,Late Promoters, Genetic,Middle Promoters, Genetic,Promoter Regions,Promoter, Genetic,Promotor Regions,Promotor, Genetic,Pseudopromoter, Genetic,Early Promoter, Genetic,Genetic Late Promoter,Genetic Middle Promoters,Genetic Promoter,Genetic Promoter Region,Genetic Promoter Regions,Genetic Promoters,Genetic Promotor,Genetic Promotors,Genetic Pseudopromoter,Genetic Pseudopromoters,Late Promoter, Genetic,Middle Promoter, Genetic,Promoter Region,Promoter Region, Genetic,Promoter, Genetic Early,Promoter, rRNA,Promoters, Genetic,Promoters, Genetic Middle,Promoters, rRNA,Promotor Region,Promotors, Genetic,Pseudopromoters, Genetic,Region, Genetic Promoter,Region, Promoter,Region, Promotor,Regions, Genetic Promoter,Regions, Promoter,Regions, Promotor,rRNA Promoters
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
D004269	DNA, Bacterial	Deoxyribonucleic acid that makes up the genetic material of bacteria.	Bacterial DNA
D004274	DNA, Recombinant	Biologically active DNA which has been formed by the in vitro joining of segments of DNA from different sources. It includes the recombination joint or edge of a heteroduplex region where two recombining DNA molecules are connected.	Genes, Spliced,Recombinant DNA,Spliced Gene,Recombinant DNA Research,Recombination Joint,DNA Research, Recombinant,Gene, Spliced,Joint, Recombination,Research, Recombinant DNA,Spliced Genes
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
D005798	Genes, Bacterial	The functional hereditary units of BACTERIA.	Bacterial Gene,Bacterial Genes,Gene, Bacterial
D000642	Ammonia-Lyases	Enzymes that catalyze the formation of a carbon-carbon double bond by the elimination of AMMONIA. EC 4.3.1.	Ammonia Lyase,Ammonia-Lyase,Ammonia Lyases,Lyase, Ammonia
D001426	Bacterial Proteins	Proteins found in any species of bacterium.	Bacterial Gene Products,Bacterial Gene Proteins,Gene Products, Bacterial,Bacterial Gene Product,Bacterial Gene Protein,Bacterial Protein,Gene Product, Bacterial,Gene Protein, Bacterial,Gene Proteins, Bacterial,Protein, Bacterial,Proteins, Bacterial