α/β coiled coils

eLife

Andrei N Lupas¹  Ioanna Karamichali¹  Birte Hernandez Alvarez¹  Jens Bassler¹  Marcus D Hartmann¹  Claudia T Mendler¹  Oswin Ridderbusch¹ 

[1] Department of Protein Evolution, Max Planck Institute for Developmental Biology, Tübingen, Germany;

关键词: α-helix;    fiber;    heptad repeat;    sequence periodicity;    supercoil;   

DOI  :  10.7554/eLife.11861

来源: DOAJ

【 摘 要 】

Coiled coils are the best-understood protein fold, as their backbone structure can uniquely be described by parametric equations. This level of understanding has allowed their manipulation in unprecedented detail. They do not seem a likely source of surprises, yet we describe here the unexpected formation of a new type of fiber by the simple insertion of two or six residues into the underlying heptad repeat of a parallel, trimeric coiled coil. These insertions strain the supercoil to the breaking point, causing the local formation of short β-strands, which move the path of the chain by 120° around the trimer axis. The result is an α/β coiled coil, which retains only one backbone hydrogen bond per repeat unit from the parent coiled coil. Our results show that a substantially novel backbone structure is possible within the allowed regions of the Ramachandran space with only minor mutations to a known fold.

【 授权许可】

Unknown