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spinqualitylabelsall models PDB ID 2zta Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image
2zta, resolution 1.80Å ()
Non-Standard Residues:
Structural annotation: Resources: UniProt : P03069
Resources:	FirstGlance, OCA, RCSB, PDBsum
Coordinates:	save as pdb, mmCIF, xml

GCN4 - The Leucine ZipperGCN4 - The Leucine Zipper

Blah blah information about leucine zipper GCN4.

spinqualitylabelsall models PDB ID 1ysa Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image
1ysa, resolution 2.90Å ()
Structural annotation: Resources: CATH : 1Ysac00, 1Ysad00 InterPro : Ipr011616, Ipr004827 Pfam : PF00170 SCOP : d1ysac_, d1ysad_ UniProt : P03069
Functional annotation: Cellular component: nucleus Biological process: positive regulation of gene-specific transcription involved in unfolded protein response amino acid biosynthetic process regulation of transcription, DNA-dependent transcription regulation of transcription from RNA polymerase II promoter Molecular function: protein dimerization activity transcription factor activity DNA binding sequence-specific DNA binding
Evolutionary conservation: Toggle Conservation Colors: Rows = identical sequences: Further Information: Caveats, Explanation, Complete Results at ConSurfDB
Resources:	FirstGlance, OCA, RCSB, PDBsum
Coordinates:	save as pdb, mmCIF, xml

StructureStructure

GCN4 (PDB 2zta by itself, 1ysa bound to DNA) is a eukaryotic transcription factor first isolated from Saccharomyces cerevisiae, also known as Baker's Yeast. CITE CITE CITE It is composed of two identical 52 residue alpha helix chains that grouped together to form a dimer. The dimer binds through interlocking leucine amino acids in the C terminal ends, while pinching in on the major groove of DNA in the N terminal end. 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 RepeatHeptad Repeat

GCN4 is said to have a heptad repeat, or seven unit repeated sequence. Here the heptad repeat is a leucine, every seven units. When the structure of the alpha helices is taken into account, it is clear that each leucine is being stacked on top of the last one, every seven units. This creates the zipper-like repeated projections from the two polypeptide chains. Below we see a pictorial representation of the sequence of amino acids as we look down the length of the coiled coil structure.

Image 1:A pictorial representation of the heptad repeat. By following through the wheels alphabetically, it is clear how the leucines will stack every 7 units. The apostrophe denotes the other subunit.(from Kgutwin in Wikipedia Commons http://commons.wikimedia.org/wiki/File:Coiledcoil-wheelcartoon.gif)

At every a and a' we have a Leucine, while at the d and d' locations we typically see valine.

See AlsoSee Also

2zta 1ysa