delta. -aminolevulinic acid dehydratase deficiency can cause. delta. -aminolevulinate auxotrophy in Escherichia coli

Journal Article · Tue Jan 01 04:00:00 EST 1991 · Journal of Bacteriology; (USA)

OSTI ID:5545816

O'Neill, G P; Michelsen, U; Soll, D ^[1]; Thorbjarnardottir, S; Palsson, S; Eggertsson, G ^[2]

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1. Yale Univ., New Haven, CT (USA)
2. Univ. of Iceland (Iceland)

Ethylmethane sulfonate-induced mutants of several Escherichia coli strains that required {delta}-aminolevulinic acid (ALA) for growth were isolated by penicillin enrichment or by selection for respiratory-defective strains resistant to the aminoglycoside antibiotic kanamycin. Three classes of mutants were obtained. Two-thirds of the strains were mutants in hemA. Representative of a third of the mutations was the hem-201 mutation. This mutation was mapped to min 8.6 to 8.7. Complementation of the auxotrophic phenotype by wild-type DNA from the corresponding phage 8F10 allowed the isolation of the gene. DNA sequence analysis revealed that the hem-201 gene encoded ALA dehydratase and was similar to a known hemB gene of E. coli. Complementation studies of hem-201 and hemB1 mutant strains with various hem-201 gene subfragments showed that hem-201 and the previously reported hemB1 mutation are in the same gene and that no other gene is required to complement the hem-201 mutant. ALA-forming activity from glutamate could not be detected by in vitro or in vivo assays. Extracts of hem-201 cells had drastically reduce ALA dehydratase levels, while cells transformed with the plasmid-encoded wild-type gene possessed highly elevated enzyme levels. The ALA requirement for growth, the lack of any ALA-forming enzymatic activity, and greatly reduced ALA dehydratase activity of the hem-201 strain suggest that a diffusible product of an enzyme in the heme biosynthetic pathway after ALA formation is involved in positive regulation of ALA biosynthesis. Analysis of another class of ALA-requiring mutants showed that the auxotrophy of the hem-205 mutant could be relieved by either methionine or cysteine and that the mutation maps in the cysG gene, which encodes uroporphyrinogen III methylase. The properties of these nonleaky ALA-requiring strains suggest that ALA is involved more extensively in E. coli intermediary metabolism than has been appreciated to date.

• OSTI ID: 5545816
• Journal Information: Journal of Bacteriology; (USA), Journal Name: Journal of Bacteriology; (USA) Vol. 173:1; ISSN JOBAA; ISSN 0021-9193
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
550400 -- Genetics
560300 -- Chemicals Metabolism & Toxicology
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
BACTERIA
BIOLOGICAL PATHWAYS
CARBON-OXYGEN LYASES
CELL CONSTITUENTS
DNA
DNA SEQUENCING
ENZYME ACTIVITY
ENZYMES
ESCHERICHIA COLI
ESTERS
GENETIC MAPPING
HYDRO-LYASES
LYASES
MAPPING
METABOLISM
MICROORGANISMS
MUTANTS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PLASMIDS
STRUCTURAL CHEMICAL ANALYSIS
SULFONIC ACID ESTERS