Saccharomyces cerevisiae has two homologous hexokinases, I and II; they are 78% identical at the amino acid level. Either enzyme allows yeast cells to ferment fructose. Mutant strains without any hexokinase can still grow on glucose by using a third enzyme, glucokinase. Hexokinase II has been implicated in the control of catabolite repression in yeasts. We constructed null mutations in both hex...

Gene replacement by transformation, employing selective genetic recombination techniques, has been used to delete or disrupt the qa-x, qa-y and qa-1S genes of the qa gene cluster of Neurospora crassa. The growth characteristics of the strain carrying the deletion of the qa-y gene support earlier evidence that this gene encodes a quinic acid permease. The strain containing the deletion of the qa...

Small non-coding RNAs (ncRNAs) are important components of many regulatory pathways in bacteria and play key roles in regulating factors important for virulence. Carbon catabolite repression control is modulated by small RNAs (crcZ or crcZ and crcY) in Pseudomonas aeruginosa and Pseudomonas putida. In this study, we demonstrate that expression of crcZ and crcX (formerly designated psr1 and psr2...

In Klebsiella aerogenes P-galactosidase and histidase are subject to strong catabolite repression by glucose in the presence of a good source of nitrogen. Under conditions of nitrogen limitation, the catabolite repression of histidase is relieved, while fi-galactosidase remains strongly repressed. Exogenous adenosine 3’, 5’-monophosphate relieves the catabolite repression of both histidase and ...

The mechanisms by which environmental carbon sources regulate biofilm formation are poorly understood. This study investigates the roles of glucose and the catabolite repression system in Serratia marcescens biofilm formation. The abilities of this opportunistic pathogen to proliferate in a wide range of environments, to cause disease, and to resist antimicrobials are linked to its ability to f...

The effects of induction and of transient and catabolite repression on lac-specific RNA in cells of Escherichia coli were investigated. The rate of Zac-specific RNA synthesis increases linearly for 3 min after induction and then becomes constant. The accumulation of RNA complementary to the promoter proximal tat 2 gene begins before accumulation of RNA complementary to the promoter distal lac Y...

The effects of induction and of transient and catabolite repression on lac-specific RNA in cells of Escherichia coli were investigated. The rate of Zac-specific RNA synthesis increases linearly for 3 min after induction and then becomes constant. The accumulation of RNA complementary to the promoter proximal tat 2 gene begins before accumulation of RNA complementary to the promoter distal lac Y...

This paper describes the characterization of an intracellular beta-glucosidase enzyme BGLII (Cel1a) and its gene (bgl2) from the cellulolytic fungus Trichoderma reesei (Hypocrea jecorina). The expression pattern of bgl2 is similar to that of other cellulase genes known from this fungus, and the gene would appear to be under the control of carbon catabolite repression mediated by the cre1 gene. ...

There are two primary levels of control of the expression of the fructanase gene (fruA) of Streptococcus mutans: induction by levan, inulin, or sucrose and repression in the presence of glucose and other readily metabolized sugars. The goals of this study were to assess the functionality of putative cis-acting regulatory elements and to begin to identify the trans-acting factors involved in ind...