TY - JOUR
T1 - Atomic structure of a tryptophan-zipper pentamer
AU - Liu, Jie
AU - Yong, Wei
AU - Deng, Yiqun
AU - Kallenbach, Neville R.
AU - Lu, Min
PY - 2004/11/16
Y1 - 2004/11/16
N2 - Coiled-coil motifs are ubiquitous mediators of specific protein-protein interactions through the formation of interlocking hydrophobic seams between α-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, α-helical pentamer in water at physiological pH. Its 1.45-Å 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 ≈8-Å-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.
AB - Coiled-coil motifs are ubiquitous mediators of specific protein-protein interactions through the formation of interlocking hydrophobic seams between α-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, α-helical pentamer in water at physiological pH. Its 1.45-Å 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 ≈8-Å-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.
KW - Coiled coils
KW - Protein design
KW - Protein structure
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U2 - 10.1073/pnas.0405319101
DO - 10.1073/pnas.0405319101
M3 - Article
C2 - 15520380
AN - SCOPUS:9244223563
SN - 0027-8424
VL - 101
SP - 16156
EP - 16161
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 46
ER -