2wpz: Difference between revisions
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==GCN4 | ==GCN4 leucine zipper mutant with two VxxNxxx motifs coordinating chloride== | ||
<StructureSection load='2wpz' size='340' side='right' caption='[[2wpz]], [[Resolution|resolution]] 1.25Å' scene=''> | <StructureSection load='2wpz' size='340' side='right' caption='[[2wpz]], [[Resolution|resolution]] 1.25Å' scene=''> | ||
== Structural highlights == | == Structural highlights == | ||
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[[Category: Activator]] | [[Category: Activator]] | ||
[[Category: Amino-acid biosynthesis]] | [[Category: Amino-acid biosynthesis]] | ||
[[Category: Coiled coil]] | |||
[[Category: Dna-binding]] | [[Category: Dna-binding]] | ||
[[Category: Ion coordination]] | [[Category: Ion coordination]] |
Revision as of 12:11, 26 September 2018
GCN4 leucine zipper mutant with two VxxNxxx motifs coordinating chlorideGCN4 leucine zipper mutant with two VxxNxxx motifs coordinating chloride
Structural highlights
Publication Abstract from PubMedMost core residues of coiled coils are hydrophobic. Occasional polar residues are thought to lower stability, but impart structural specificity. The coiled coils of trimeric autotransporter adhesins (TAAs) are conspicuous for their large number of polar residues in position d of the core, which often leads to their prediction as natively unstructured regions. The most frequent residue, asparagine (N@d), can occur in runs of up to 19 consecutive heptads, frequently in the motif [I/V]xxNTxx. In the Salmonella TAA, SadA, the core asparagines form rings of interacting residues with the following threonines, grouped around a central anion. This conformation is observed generally in N@d layers from trimeric coiled coils of known structure. Attempts to impose a different register on the motif show that the asparagines orient themselves specifically into the core, even against conflicting information from flanking domains. When engineered into the GCN4 leucine zipper, N@d layers progressively destabilized the structure, but zippers with 3 N@d layers still folded at high concentration. We propose that N@d layers maintain the coiled coils of TAAs in a soluble, export-competent state during autotransport through the outer membrane. More generally, we think that polar motifs that are both periodic and conserved may often reflect special folding requirements, rather than an unstructured state of the mature proteins. A coiled-coil motif that sequesters ions to the hydrophobic core.,Hartmann MD, Ridderbusch O, Zeth K, Albrecht R, Testa O, Woolfson DN, Sauer G, Dunin-Horkawicz S, Lupas AN, Alvarez BH Proc Natl Acad Sci U S A. 2009 Oct 6;106(40):16950-5. Epub 2009 Sep 23. PMID:19805097[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences |
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