Characterization of chlD gene required for molybdenum utilization in Escherichia coli

Conference · Thu May 01 04:00:00 EDT 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:5144818

Scott, D J; Amy, N K

ChlD mutants in E. coli have altered biochemical utilization of molybdenum from wild type cells. These mutants have reduced nitrate reductase and molybdenum cofactor activities when grown in low concentrations of molybdenum. When molybdenum is supplemented to 100..mu..M the mutants have wild type levels of both activities. In this study they have isolated a single copy episome containing the chlD gene using interrupted mating techniques as well as a multiple copy plasmid pBR322 with an insert containing the chlD gene using cloning techniques. The introduction of these additional chlD genes into a chlD mutant healed the phenotype when grown in low molybdenum concentrations. This indicates the chlD locus encodes for a transacting gene product. The restoration of phenotype was identical for both the single copy as well as multiple copy merodiploids. The pBR322 with the insert containing the chlD gene is currently being further characterized by restriction mapping. Previous studies have shown that the expression of the chlD gene as measured by ..beta..-galactosidase activity in chlD lac operon fusion mutants was high in cells grown in low molybdenum concentrations and low in cells grown in high molybdenum concentrations. This expression was unaltered when the episome containing the chlD gene was introduced into the chlD lac operon fusion mutant. This indicates that the product of the chlD gene is not required for regulation by molybdenum. The effect of multiple copies of the chlD gene on the expression of the chlD lac operon fusion is presently being studied. The eventual goal of these studies is to determine the function of the chlD gene in the activation of molybdenum.

• Research Organization: Univ. of California, Berkeley
• OSTI ID: 5144818
• Report Number(s): CONF-8606151-
• Conference Information: Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Journal Volume: 45:6
• Country of Publication: United States
• Language: English

Related Subjects

550500 -- Metabolism
560302* -- Chemicals Metabolism & Toxicology-- Microorganisms-- (-1987)
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
BACTERIA
BIOLOGICAL FUNCTIONS
CELL CONSTITUENTS
CLONING
ELEMENTS
ENZYME ACTIVITY
ENZYMES
ESCHERICHIA COLI
FUNCTIONS
GALACTOSIDASE
GENE OPERONS
GENE REGULATION
GENES
GENETIC MAPPING
GLYCOSYL HYDROLASES
GROWTH
HYDROLASES
MAPPING
METABOLISM
METALS
MICROORGANISMS
MOLYBDENUM
MUTANTS
O-GLYCOSYL HYDROLASES
PHENOTYPE
PLASMIDS
TRANSITION ELEMENTS