7BAT

A hexameric barrel state of a de novo coiled-coil assembly: CC-Type2-(GgIaId)4

Summary for 7BAT

• Entry DOI: 10.2210/pdb7bat/pdb
• Descriptor: CC-Type2-(GgIaId)4, N-PROPANOL (3 entities in total)
• Functional Keywords: alpha, helical, barrel, hexamer, de novo protein
• Biological source: synthetic construct
• Total number of polymer chains: 3
• Total formula weight: 9716.59

Authors

Martin, F.J.O.,Dawson, W.M.,Shelley, K.,Brady, R.L.,Woolfson, D.N. (deposition date: 2020-12-16, release date: 2021-04-28, Last modification date: 2021-11-17)

Primary citation

Dawson, W.M.,Martin, F.J.O.,Rhys, G.G.,Shelley, K.L.,Brady, R.L.,Woolfson, D.N.
Coiled coils 9-to-5: rational de novo design of alpha-helical barrels with tunable oligomeric states.
Chem Sci, 12:6923-6928, 2021

PubMed Abstract: The rational design of linear peptides that assemble controllably and predictably in water is challenging. Short sequences must encode unique target structures and avoid alternative states. However, the non-covalent forces that stabilize and discriminate between states are weak. Nonetheless, for α-helical coiled-coil assemblies considerable progress has been made in rational design. In these, sequence repeats of nominally hydrophobic () and polar () residues, , direct the assembly of amphipathic helices into dimeric to tetrameric bundles. Expanding this pattern to can produce larger α-helical barrels. Here, we show that pentameric to nonameric barrels are accessed by varying the residue at one of the sites. In peptides with four L/I-K-E-I-A-x-Z repeats, decreasing the size of Z from threonine to serine to alanine to glycine gives progressively larger oligomers. X-ray crystal structures of the resulting α-helical barrels rationalize this: side chains at Z point directly into the helical interfaces, and smaller residues allow closer helix contacts and larger assemblies.

PubMed: 34745518
DOI: 10.1039/d1sc00460c

Experimental method

X-RAY DIFFRACTION (1.77 Å)