6YAZ

Crystal structure of a parallel hexameric coiled coil CC-Type2-(TaId)5

Summary for 6YAZ

• Entry DOI: 10.2210/pdb6yaz/pdb
• Descriptor: CC-Type2-(TaId)5 (2 entities in total)
• Functional Keywords: alpha-helical barrel, de novo protein, de novo peptide, coiled coil, designed peptide, designed protein
• Biological source: synthetic construct
• Total number of polymer chains: 12
• Total formula weight: 47153.93

Authors

Scott, A.J.,Brady, R.L.,Woolfson, D.N. (deposition date: 2020-03-15, release date: 2021-04-07, Last modification date: 2024-11-13)

Primary citation

Scott, A.J.,Niitsu, A.,Kratochvil, H.T.,Lang, E.J.M.,Sengel, J.T.,Dawson, W.M.,Mahendran, K.R.,Mravic, M.,Thomson, A.R.,Brady, R.L.,Liu, L.,Mulholland, A.J.,Bayley, H.,DeGrado, W.F.,Wallace, M.I.,Woolfson, D.N.
Constructing ion channels from water-soluble alpha-helical barrels.
Nat.Chem., 13:643-650, 2021

PubMed Abstract: The design of peptides that assemble in membranes to form functional ion channels is challenging. Specifically, hydrophobic interactions must be designed between the peptides and at the peptide-lipid interfaces simultaneously. Here, we take a multi-step approach towards this problem. First, we use rational de novo design to generate water-soluble α-helical barrels with polar interiors, and confirm their structures using high-resolution X-ray crystallography. These α-helical barrels have water-filled lumens like those of transmembrane channels. Next, we modify the sequences to facilitate their insertion into lipid bilayers. Single-channel electrical recordings and fluorescent imaging of the peptides in membranes show monodisperse, cation-selective channels of unitary conductance. Surprisingly, however, an X-ray structure solved from the lipidic cubic phase for one peptide reveals an alternative state with tightly packed helices and a constricted channel. To reconcile these observations, we perform computational analyses to compare the properties of possible different states of the peptide.

PubMed: 33972753
DOI: 10.1038/s41557-021-00688-0

Experimental method

X-RAY DIFFRACTION (1.94 Å)