Regulatory mutants and control of cysteine biosynthetic enzymes in Salmonella typhimurium

Journal Article · Thu Jan 01 04:00:00 EST 1976 · J. Bacteriol.; (United States)

OSTI ID:7368369

Borum, P R; Monty, K J

The cysB region in Salmonella typhimurium regulates in a positive manner the noncontiguous structural genes for the enzymes responsible for sulfate reduction in cysteine biosynthesis. We treated three cysB mutants with chemical mutagens and selected 81 secondary mutants in which the inability to utilize sulfate was suppressed. Growth experiments on the suppressed mutants showed that the original loss of sulfate utilization had been corrected to varying degrees and that portions of the pathway had been established in abnormal relationships to one another. Sixty of the suppressed mutations were mapped via transductional analysis, and each was very closely linked to the original cysB mutation. We demonstrated that the cysB product functions in the regulation of the cysteine biosynthetic enzymes during both logarithmic growth and stationary phase. Mutation can alter the regulatory response of one enzyme in either an upward or downward direction while the regulation of other enzymes in the pathway remains unchanged. These data are consistent with the idea of a multivalent or multisite regulator molecule. (auth)

• Research Organization: Univ. of Tennessee, Knoxville
• OSTI ID: 7368369
• Journal Information: J. Bacteriol.; (United States), Journal Name: J. Bacteriol.; (United States) Vol. 125:1; ISSN JOBAA
• Country of Publication: United States
• Language: English

Related Subjects

550200 -- Biochemistry
550400* -- Genetics
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
BACTERIA
BIOLOGY
BIOSYNTHESIS
CARBOXYLIC ACIDS
CONTROL
CYSTEINE
ENZYMES
GENETICS
MICROORGANISMS
MUTAGENS
MUTANTS
MUTATIONS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
OXYGEN COMPOUNDS
SALMONELLA
SALMONELLA TYPHIMURIUM
SULFATES
SULFUR COMPOUNDS
SYNTHESIS
THIOLS