Identification of the enzymatic basis for. delta. -aminolevulinic acid auxotrophy in a hemA mutant of escherichia coli

Journal Article · Thu Jun 01 00:00:00 EDT 1989 · Journal of Bacteriology; (USA)

OSTI ID:7191671

Avissar, Y J; Beale, S I ^[1]

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1. Brown Univ., Providence, RI (USA)

The hemA mutation of Escherichia coli K-12 confers a requirement for {delta}-aminolevulinic acid (ALA). Cell extract prepared from the hemA strain SASX41B was incapable of producing ALA from either glutamate or glutamyl-tRNA, whereas extract of the hem{sup +} strain HB101 formed colorimetrically detectable amounts of ALA and transferred label from 1-({sup 14}C)glutamate and 3,4-({sup 3}H)glutamyl-tRNA to ALA. Extracts of both strains converted glutamate-1-semialdehyde to ALA and were capable of aminoacylating tRNA{sup Glu}. Glutamyl-tRNA formed by extracts of both strains could be converted to ALA by the extract of hem{sup +} cells. The extract of hemA cells did not convert glutamyl-tRNA formed by either strain to ALA. However, the hemA cell extract, when supplemented in vitro with glutamyl-tRNA dehydrogenase isolated from Chlorella vulgaris cells, formed about as much ALA as did the unsupplemented hem{sup +} cell extract. We conclude from these observations that the enzyme activity that is lacking in the ALA auxotrophic strain carrying the hemA mutation is that of glutamyl-tRNA dehydrogenase.

• OSTI ID: 7191671
• Journal Information: Journal of Bacteriology; (USA), Vol. 171:6; ISSN 0021-9193
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
ESCHERICHIA COLI
MOLECULAR BIOLOGY
OXIDOREDUCTASES
GENES
AMINOLEVULINIC ACID
CARBON 14 COMPOUNDS
CHLORELLA
ENZYME ACTIVITY
MUTANTS
TRACER TECHNIQUES
TRANSFER RNA
ALGAE
AMINO ACIDS
BACTERIA
CARBOXYLIC ACIDS
CHLOROPHYCOTA
ENZYMES
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MICROORGANISMS
NUCLEIC ACIDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
PLANTS
RNA
UNICELLULAR ALGAE
550201* - Biochemistry- Tracer Techniques