Biomaterial Database

Stimulation in trans of synthesis of E. coli gal operon enzymes by lambdoid phages during low catabolite repression. 1976

E Petit-Koskas, and G Contesse

The infection of E. coli cells with different lambdoïd prophages triggers a stimulation of galactokinase synthesis when cells are grown in a medium giving rise to a mild catabolite repression (tryptone broth) with an inducer of the gal operon (fucose). These results show that during phage infection (or induction) some factor acting in trans is produced which is able to overcome efficiently catabolite repression of the kinase cistron. Using different strains of lambdapbio252 (pam, qam, "hl), lambdapbio256Hl and lambdaNNS7 we have concluded that the factor is the N gene product which is known for its anti- p(rho) action. Studies of the whole gal operon in the same conditions show that epimerase unlike transferase and galactokinase is practically insensitive to catabolite repression by tryptone broth and that viral development has a low effect on it. This indicates that there is an internal modulation of gal operon expression. A mRNA termination site sensitive to the p factor is known in the gal operon between galE and galT. Another site weaker than this one might exist between galE and operator-promoter region.

UI	MeSH Term	Description	Entries
D009713	Nucleotidyltransferases	A class of enzymes that transfers nucleotidyl residues. EC 2.7.7.	Nucleotidyltransferase
D009876	Operon	In bacteria, a group of metabolically related genes, with a common promoter, whose transcription into a single polycistronic MESSENGER RNA is under the control of an OPERATOR REGION.	Operons
D003090	Coliphages	Viruses whose host is Escherichia coli.	Escherichia coli Phages,Coliphage,Escherichia coli Phage,Phage, Escherichia coli,Phages, Escherichia coli
D004794	Enzyme Repression	The interference in synthesis of an enzyme due to the elevated level of an effector substance, usually a metabolite, whose presence would cause depression of the gene responsible for enzyme synthesis.	Repression, Enzyme
D004926	Escherichia coli	A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.	Alkalescens-Dispar Group,Bacillus coli,Bacterium coli,Bacterium coli commune,Diffusely Adherent Escherichia coli,E coli,EAggEC,Enteroaggregative Escherichia coli,Enterococcus coli,Diffusely Adherent E. coli,Enteroaggregative E. coli,Enteroinvasive E. coli,Enteroinvasive Escherichia coli
D005643	Fucose	A six-member ring deoxysugar with the chemical formula C6H12O5. It lacks a hydroxyl group on the carbon at position 6 of the molecule.	Deoxygalactose,alpha-Fucose,alpha Fucose
D005694	UTP-Hexose-1-Phosphate Uridylyltransferase	An enzyme that catalyzes the synthesis of UDPgalactose from UTP and galactose-1-phosphate. It is present in low levels in fetal and infant liver, but increases with age, thereby enabling galactosemic infants who survive to develop the capacity to metabolize galactose. EC 2.7.7.10.	Galactosephosphate Uridylyltransferase,UDP Galactose Pyrophosphorylase,Galactose-1-Phosphate Uridyltransferase,Galactose 1 Phosphate Uridyltransferase,Galactose Pyrophosphorylase, UDP,Pyrophosphorylase, UDP Galactose,UTP Hexose 1 Phosphate Uridylyltransferase,Uridyltransferase, Galactose-1-Phosphate,Uridylyltransferase, Galactosephosphate,Uridylyltransferase, UTP-Hexose-1-Phosphate
D014764	Viral Proteins	Proteins found in any species of virus.	Gene Products, Viral,Viral Gene Products,Viral Gene Proteins,Viral Protein,Protein, Viral,Proteins, Viral