5apq
From Proteopedia
Sequence IENKAD inserted between GCN4 adaptors - Structure A6
Structural highlights
FunctionGCN4_YEAST Is a transcription factor that is responsible for the activation of more than 30 genes required for amino acid or for purine biosynthesis in response to amino acid or purine starvation. Binds and recognize the DNA sequence: 5'-TGA[CG]TCA-3'. Publication Abstract from PubMedCoiled coils are the best-understood protein fold, as their backbone structure can uniquely be described by parametric equations. This level of understanding has allowed their manipulation in unprecedented detail. They do not seem a likely source of surprises, yet we describe here the unexpected formation of a new type of fiber by the simple insertion of two or six residues into the underlying heptad repeat of a parallel, trimeric coiled coil. These insertions strain the supercoil to the breaking point, causing the local formation of short beta-strands, which move the path of the chain by 120 degrees around the trimer axis. The result is an alpha/beta coiled coil, which retains only one backbone hydrogen bond per repeat unit from the parent coiled coil. Our results show that a substantially novel backbone structure is possible within the allowed regions of the Ramachandran space with only minor mutations to a known fold. alpha/beta coiled coils.,Hartmann MD, Mendler CT, Bassler J, Karamichali I, Ridderbusch O, Lupas AN, Hernandez Alvarez B Elife. 2016 Jan 15;5. pii: e11861. doi: 10.7554/eLife.11861. PMID:26771248[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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