6G69

Crystal structure of a parallel seven-helix coiled coil CC-Type2-IL-Sg-L17E

Summary for 6G69

• Entry DOI: 10.2210/pdb6g69/pdb
• Descriptor: CC-Type2-IL-Sg-L17E, (4S)-2-METHYL-2,4-PENTANEDIOL, (4R)-2-METHYLPENTANE-2,4-DIOL, ... (4 entities in total)
• Functional Keywords: de novo, coiled coil, alpha-helical bundle, synthetic construct, de novo protein
• Biological source: synthetic construct
• Total number of polymer chains: 14
• Total formula weight: 46998.45

Authors

Rhys, G.G.,Brady, R.L.,Woolfson, D.N. (deposition date: 2018-04-01, release date: 2018-10-17, Last modification date: 2019-01-23)

Primary citation

Rhys, G.G.,Wood, C.W.,Lang, E.J.M.,Mulholland, A.J.,Brady, R.L.,Thomson, A.R.,Woolfson, D.N.
Maintaining and breaking symmetry in homomeric coiled-coil assemblies.
Nat Commun, 9:4132-4132, 2018

PubMed Abstract: In coiled-coil (CC) protein structures α-helices wrap around one another to form rope-like assemblies. Most natural and designed CCs have two-four helices and cyclic (C) or dihedral (D) symmetry. Increasingly, CCs with five or more helices are being reported. A subset of these higher-order CCs is of interest as they have accessible central channels that can be functionalised; they are α-helical barrels. These extended cavities are surprising given the drive to maximise buried hydrophobic surfaces during protein folding and assembly in water. Here, we show that α-helical barrels can be maintained by the strategic placement of β-branched aliphatic residues lining the lumen. Otherwise, the structures collapse or adjust to give more-complex multi-helix assemblies without C or D symmetry. Nonetheless, the structural hallmark of CCs-namely, knobs-into-holes packing of side chains between helices-is maintained leading to classes of CCs hitherto unobserved in nature or accessed by design.

PubMed: 30297707
DOI: 10.1038/s41467-018-06391-y

Experimental method

X-RAY DIFFRACTION (2.2 Å)