Cross-linking reveals laminin coiled-coil architecture.
Laminin, an ∼800-kDa heterotrimeric protein, is a major functional component of the extracellular matrix, contributing to tissue development and maintenance. The unique architecture of laminin is not currently amenable to determination at high resolution, as its flexible and narrow segments complicate both crystallization and single-particle reconstruction by electron microscopy. Therefore, we used cross-linking and MS, evaluated using computational methods, to address key questions regarding laminin quaternary structure. This approach was particularly well suited to the ∼750-Å coiled coil that mediates trimer assembly, and our results support revision of the subunit order typically presented in laminin schematics. Furthermore, information on the subunit register in the coiled coil and cross-links to downstream domains provide insights into the self-assembly required for interaction with other extracellular matrix and cell surface proteins.
Department of Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel.
Gad
G
Armony
Department of Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel.|The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel.
Etai
E
Jacob
Department of Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel.
Toot
T
Moran
The Nancy and Stephen Grand Israel National Center for Personalized Medicine, Weizmann Institute of Science, Rehovot 7610001, Israel.
Yishai
Y
Levin
Biological Research Support, Weizmann Institute of Science, Rehovot 7610001, Israel.
Tevie
T
Mehlman
Department of Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel.
Yaakov
Y
Levy
Department of Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel; deborah.fass@weizmann.ac.il.
Deborah
D
Fass
D000818:Animals; D019295:Computational Biology / Q000379:methods; D003432:Cross-Linking Reagents / Q000737:chemistry*; D007797:Laminin / Q000737:chemistry*; D013058:Mass Spectrometry; D051379:Mice; D008958:Models, Molecular; D020836:Protein Structure, Quaternary
D003432:Cross-Linking Reagents; D007797:Laminin
coiled coil; cross-linking; extracellular matrix; laminin; mass spectrometry