A regulatory gene and a structural gene for alaninase in Escherichia coli

1973 ◽  
Vol 121 (4) ◽  
pp. 369-374 ◽  
Author(s):  
R. H. J. Beelen ◽  
A. M. Feldmann ◽  
H. J. W. Wijsman
Keyword(s):  
Escherichia Coli ◽  
Structural Gene ◽  
Regulatory Gene

scholarly journals ON THE EVOLUTION OF NEW METABOLIC FUNCTIONS IN DIPLOID ORGANISMS

Genetics ◽  
1980 ◽  
Vol 96 (4) ◽  
pp. 1007-1017
Author(s):  
Barry G Hall
Keyword(s):  
Escherichia Coli ◽  
Structural Gene ◽  
Regulatory Gene ◽  
Selective Advantage ◽  
Negative Control ◽  
Wild Type ◽  
Metabolic Functions ◽  
Lactose Utilization

ABSTRACT Evolution of lactose utilization via the ebg system of Escherichia coli requires both structural gene (ebgA) and regulatory gene (ebgR) mutations. Because evolution of new metabolic functions in diploids might be subject to constraints not present in haploid organisms, merodiploid strains carrying a wild-type and an evolved ebgA allele, or a wild-type and an evolved ebgR allele were constructed. I show that heterozygosity at ebgA does not significantly affect the selective advantage of the evolved ebgA allele; whereas heterozygosity at ebgR eliminates the selective advantage of the evolved ebgR allele. It is suggested that, in diploid organisms, evolution of new functions for systems under negative control would be very difficult.

scholarly journals A NEW MAP LOCATION FOR THE ilvB LOCUS OF ESCHERICHIA COLI

Genetics ◽  
1980 ◽  
Vol 96 (1) ◽  
pp. 59-77
Author(s):  
Thomas C Newman ◽  
Mark Levinthal
Keyword(s):  
Escherichia Coli ◽  
Structural Gene ◽  
Acetolactate Synthase ◽  
Deletion Mapping ◽  
Donor Strain ◽  
E Coli ◽  
Linkage Of Genes ◽  
Map Location ◽  
New Alleles

ABSTRACT We isolated, in E. coli K12, new alleles of the ilvB locus, the structural gene for acetolactate synthase isoenzyme I, and showed them to map at or near the ilvB619 site. The map position of the ilvB locus was redetermined because plasmids containing the ilvC-cya portion of the chromosome did not complement mutations at the ilvB locus. Furthermore, diploids for the ilvEDAC genes formed with these plasmids in an ilvHI background facilitated the isolation of the new ilvB alleles. The ilvB locus was remapped and found to be located at 81.5 minutes, between the uhp and dnaA loci. This location was determined by two- and three-point transductional crosses, deletion mapping and complementation with newly isolated plasmids. One of the new alleles of the ilvB gene is a mu-1 insertion. When present in the donor strain, this allele interferes with the linkage of genes flanking the mu-1 insertion, as well as the linkage of genes to either side of the mu-1 insertion.

scholarly journals A GENETICALLY DISTINCT FORM OF CYCLIC AMP PHOSPHODIESTERASE ASSOCIATED WITH CHROMOMERE 3D4 IN DROSOPHILA MELANOGASTER

Genetics ◽  
1979 ◽  
Vol 91 (3) ◽  
pp. 521-535
Author(s):  
John A Kiger ◽  
Eric Golanty
Keyword(s):  
Drosophila Melanogaster ◽  
Cyclic Amp ◽  
Structural Gene ◽  
Regulatory Gene ◽  
Heat Stability ◽  
Normal Female ◽  
Dependent Manner ◽  
Cyclic Amp Phosphodiesterase ◽  
Heat Stable ◽  
Camp Levels

ABSTRACT Two cyclic AMP phosphodiesterase enzymes (E.C.3.1.4.17) are present in homogenates of adult Drosophila melanogaster. The two enzymes differ from one another in heat stability, affinity for Mg++, Ca++ activation and molecular weight. They do not differ markedly in their affinities for cyclic AMP, and both exhibit anomalous Michaelis-Menten kinetics. The more heatlabile enzyme is controlled in a dosage-dependent manner by chromomere 3D4 of the X chromosome and is absent in flies that are deficient for chromomere 3D4. Chromomere 3D4 is also necessary for the maintenance of normal cAMP levels, for male fertility, and for normal female fertility and oogenesis. The structural gene(s) for the more heat-stable enzyme is located outside of chromomeres 3C12-3D4. Whether 3D4 contains a structural gene, or a regulatory gene necessary for the presence of the labile enzyme, remains to be determined.

Mapping of mglB, the structural gene of the galactose-binding protein of Escherichia coli

1981 ◽  
Vol 184 (3) ◽  
pp. 508-518 ◽  
Author(s):  
Winfried Boos ◽  
Ingrid Steinacher ◽  
Dörte Engelhardt-Altendorf
Keyword(s):  
Escherichia Coli ◽  
Structural Gene ◽  
Binding Protein
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