Tom Sandbox: Difference between revisions
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===Structure=== | ===Structure=== | ||
GCN4 is composed of two identical 58 residue alpha helix chains that grouped together to form a parallel coiled-coil dimer. The dimer binds through interlocking leucine amino acids and hydrophobic residues near the C terminus, while pinching in on the major groove of DNA in the N terminal end via basic residues. These two main domains are thus labled the leucine zipper dimerization domain and the basic DNA-binding domain. <ref> Sharma, G.; Rege, K.; Budil, D. E.; Yarmush, M. L.; Mavroidis, C. Int J Nanomedicine. 2008 December; 3(4): 505–521. </ref> The basic residues are the reason the class of binding interactions is commonly referred to as bZIP or basic region leucine zipper proteins<ref name="Voet"> Voet, Donald; Voet, Judith G.; Pratt, Charlotte W. Fundamentals of Biochemistry: Life at the Molecular Level. 3rd Ed. Hoboken, NJ: Wiley, 2008. </ref>. The X-ray structure of the 33-residue polypeptide corresponding to the leucine zipper of GCN4 was determined by Peter Kim and Thomas Alber. | GCN4 is composed of two identical 58 residue alpha helix chains that grouped together to form a parallel coiled-coil dimer. The dimer binds through interlocking leucine amino acids and hydrophobic residues near the C terminus, while pinching in on the major groove of DNA in the N terminal end via basic residues. These two main domains are thus labled the leucine zipper dimerization domain and the basic DNA-binding domain. <ref name="ph"> Sharma, G.; Rege, K.; Budil, D. E.; Yarmush, M. L.; Mavroidis, C. Int J Nanomedicine. 2008 December; 3(4): 505–521. </ref> The basic residues are the reason the class of binding interactions is commonly referred to as bZIP or basic region leucine zipper proteins<ref name="Voet"> Voet, Donald; Voet, Judith G.; Pratt, Charlotte W. Fundamentals of Biochemistry: Life at the Molecular Level. 3rd Ed. Hoboken, NJ: Wiley, 2008. </ref>. The X-ray structure of the 33-residue polypeptide corresponding to the leucine zipper of GCN4 was determined by Peter Kim and Thomas Alber. | ||
====Heptad Repeat==== | ====Heptad Repeat==== | ||
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====The Leucine Zipper==== | ====The Leucine Zipper==== | ||
The Leucine Zipper of GCN4, as expected, operates under a specific pH. It has been shown that at lower pH values the zipper will reversibly protenate and open up, losing its hydrophobic stability.<ref name="ph"/> | |||
