Transcription of these genes relies only on existing transcription factors and proceeds in the presence of synthesis inhibitors. For 10 points each:
[10h] Name these genes that mediate short-scale cell signaling. The N antiterminator is an example of these genes in the lambda phage, while c-Fos (“C-foss”) is a human one used as a marker of neuronal activation.
ANSWER: immediate early genes [or IE genes]
[10m] c-Fos can dimerize with c-Jun (“C-joon”) by forming this structural motif. Transcription factors that incorporate this motif, such as AP-1 and CREB (“creb”), contain a heptad (“HEP-tad”) repeat with two hydrophobic residues.
ANSWER: leucine zipper [accept basic leucine zipper domain; prompt on coiled coils]
[10e] The Fos-Jun leucine (“LEW-seen”) zipper is a canonical example of how this secondary structural motif can form a coiled coil. Each residue in these structures rotates about 100 degrees relative to the last.
ANSWER: alpha helix [or alpha helices; prompt on helix or helices]
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