In the case of the bacterial enzyme bearing s70, this transition, often called isomerization, does not require energy derived from ATP hydrolysis and is instead the result of a spontaneous conformational change in the DNA– enzyme complex to a more energetically favorable form.

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#Unit 11. Evolution and Behavior

Hitchhiking: Change in the frequency of an allele due to linkage with a selected allele at another locus.

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#Unit 4. Cell Communication and Cell Signaling

In the absence of Hh,

Ptc inhibits Smoothened and then degraded in proteasomes

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#Unit 5. Developmental Biology

A second glycoprotein secreted during starvation is CMF (conditioned medium factor)

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#Unit 5. Developmental Biology

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#Id: 6807

#Unit 3. Fundamental Processes

The precursor RNA for the siRNA pathway is a longer dsRNA. As a consequence of this different initial substrate, Drosha is not needed for the generation of siRNAs. Cleavage by Dicer is still required, however, and again generates a suitable 21- to 22-nucleotide RNA for incorporation into RISC.