Class I AC
Class I AC's occur in many bacteria including E. coli. This was the first class of AC to be characterized. It was observed that E. coli deprived of glucose produce cAMP that serves as an internal signal to activate expression of genes for importing and metabolizing other sugars. cAMP exerts this effect by binding the transcription factor CRP, also known as CAP. Class I AC's are large cytosolic enzymes (~100 kDa) with a large regulatory domain (~50 kDa) that indirectly senses glucose levels. As of 2012, no crystal structure is available for class I AC.
Read more about this topic: Adenylate Cyclase
Famous quotes containing the words class i and/or class:
“I do not deny that there may be other well-founded causes for the hatred which various classes feel toward politicians, but the main one seems to me that politicians are symbols of the fact that every class must take every other class into account.”
—José Ortega Y Gasset (1883–1955)
“During the long ages of class rule, which are just beginning to cease, only one form of sovereignty has been assigned to all men—that, namely, over all women. Upon these feeble and inferior companions all men were permitted to avenge the indignities they suffered from so many men to whom they were forced to submit.”
—Mary Putnam Jacobi (1842–1906)