1T8Z

Atomic Structure of A Novel Tryptophan-Zipper Pentamer

Summary for 1T8Z

• Entry DOI: 10.2210/pdb1t8z/pdb
• Related: 1eq7
• Descriptor: Major outer membrane lipoprotein, SULFATE ION, DODECAETHYLENE GLYCOL, ... (4 entities in total)
• Functional Keywords: lipoprotein, protein folding, coiled coil, pentamer, tryptophan-zipper, membrane protein
• Biological source: Escherichia coli
• Cellular location: Cell outer membrane; Lipid-anchor: P69776
• Total number of polymer chains: 5
• Total formula weight: 35144.66

Authors

Liu, J.,Yong, W.,Deng, Y.,Kallenbach, N.R.,Lu, M. (deposition date: 2004-05-13, release date: 2004-11-23, Last modification date: 2024-02-14)

Primary citation

Liu, J.,Yong, W.,Deng, Y.,Kallenbach, N.R.,Lu, M.
Atomic structure of a tryptophan-zipper pentamer.
Proc.Natl.Acad.Sci.USA, 101:16156-16161, 2004

PubMed Abstract: Coiled-coil motifs are ubiquitous mediators of specific protein-protein interactions through the formation of interlocking hydrophobic seams between alpha-helical chains. Residues that form these seams occur at the first (a) and fourth (d) positions of a characteristic 7-aa repeat and are primarily aliphatic. The potential of aromatic residues to promote helix association in a coiled coil was explored by engineering a "Trp-zipper" protein with Trp residues at all 14 a and d positions. The protein forms a discrete, stable, alpha-helical pentamer in water at physiological pH. Its 1.45-A crystal structure reveals a parallel, five-stranded coiled coil, a previously uncharacterized type of "knobs-into-holes" packing interaction between interfacial Trp side chains, and an unusual approximately 8-A-diameter axial channel lined with indole rings that is filled with polyethylene glycol 400 and water and sulfate ion molecules. The engineered Trp-zipper pentamer enlarges current views of coiled-coil assembly, molecular recognition, and protein engineering, and may serve as a soluble model for membrane ion channels.

PubMed: 15520380
DOI: 10.1073/pnas.0405319101

Experimental method

X-RAY DIFFRACTION (1.45 Å)