1887

Chapter 15 : From Lactose to Galactose

MyBook is a cheap paperback edition of the original book and will be sold at uniform, low price.

Ebook: Choose a downloadable PDF or ePub file. Chapter is a downloadable PDF file. File must be downloaded within 48 hours of purchase

Buy this Chapter
Digital (?) $7.00

Preview this chapter:
Zoom in
Zoomout

From Lactose to Galactose, Page 1 of 2

| /docserver/preview/fulltext/10.1128/9781555817763/9781555812812_Chap15-1.gif /docserver/preview/fulltext/10.1128/9781555817763/9781555812812_Chap15-2.gif

Abstract:

The hypothesis of catabolite repression predicts that energy sources other than glucose should repress glucose-sensitive enzymes in cells grown in media that limit their ability to utilize the catabolites rapidly for the synthesis of macromolecules; and in fact, partial amino acid, purine, pyrimidine, or phosphate starvation has this effect. As the names imply, in a physiological sense, induction is a positive control and catabolite repression a negative control. Nevertheless, for lac and hut (histidine degradation) and many other systems, induction actually reflects negative control at the molecular level, and in all cases catabolite repression appears to reflect positive control at the molecular level. The observation by Ullmann and Monod and independently by Perlman and Pastan that the addition of cyclic AMP can overcome the repressive effect of glucose led to the discovery that the transcription of genes coding for enzymes subject to catabolite repression requires activation by the catabolite-activating protein (CAP) charged with cyclic AMP. Glucose appears to lower the intracellular level of cyclic AMP by an as-yet-undiscovered mechanism. In short, the apparent escape from catabolite repression of histidase really reflects a phenomenon distinct from catabolite repression: the activation by glutamine synthetase (GS) of the transcription of genes coding for enzymes that can supply the cell with ammonia or glutamate.

Citation: Buttin G. 2003. From Lactose to Galactose, p 153-161. In Ullmann A (ed), Origins of Molecular Biology. ASM Press, Washington, DC. doi: 10.1128/9781555817763.ch15

Key Concept Ranking

Microbial Genetics
0.5695085
Chemicals
0.55494535
Viruses
0.55264264
Cyclic AMP
0.5428035
RNA Polymerase
0.5208333
0.5695085
Highlighted Text: Show | Hide
Loading full text...

Full text loading...

Figures

Image of Figure 1
Figure 1

1962.

Citation: Buttin G. 2003. From Lactose to Galactose, p 153-161. In Ullmann A (ed), Origins of Molecular Biology. ASM Press, Washington, DC. doi: 10.1128/9781555817763.ch15
Permissions and Reprints Request Permissions
Download as Powerpoint
Image of Figure 2
Figure 2

Between 1960 and 1965.

Citation: Buttin G. 2003. From Lactose to Galactose, p 153-161. In Ullmann A (ed), Origins of Molecular Biology. ASM Press, Washington, DC. doi: 10.1128/9781555817763.ch15
Permissions and Reprints Request Permissions
Download as Powerpoint
Image of Figure 3
Figure 3

Citation: Buttin G. 2003. From Lactose to Galactose, p 153-161. In Ullmann A (ed), Origins of Molecular Biology. ASM Press, Washington, DC. doi: 10.1128/9781555817763.ch15
Permissions and Reprints Request Permissions
Download as Powerpoint

References

/content/book/10.1128/9781555817763.chap15

This is a required field
Please enter a valid email address
Please check the format of the address you have entered.
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error