Coiled coil

A coiled coil is a structural motif in proteins in which 2–7alpha-helices are coiled together like the strands of a rope (dimers and trimers are the most common types). Many coiled coil-type proteins are involved in important biological functions such as the regulation of gene expression, e.g. transcription factors. Notable examples are the oncoproteins c-Fos and c-jun, as well as the muscle protein tropomyosin.

The possibility of coiled coils for α-keratin was initially somewhat controversial. Linus Pauling and Francis Crick independently came to the conclusion that this was possible at about the same time. In the summer of 1952, Pauling visited the laboratory in England where Crick worked. Pauling and Crick met and spoke about various topics; at one point, Crick asked whether Pauling had considered "coiled coils" (Crick came up with the term), to which Pauling said he had. Upon returning to the United States, Pauling resumed research on the topic. He concluded that coiled coils exist, and submitted a lengthy manuscript to the journal Nature in October. Pauling's son Peter Pauling worked at the same lab as Crick, and mentioned the report to him. Crick believed that Pauling had stolen his idea, and submitted a shorter note to Nature a few days after Pauling's manuscript arrived. Eventually, after some controversy and frequent correspondences, Crick's lab declared that the idea had been reached independently by both researchers, and that no intellectual theft had occurred. In his note (which was published first due to its shorter length), Crick proposed the Coiled Coil and as well as mathematical methods for determining their structure. Remarkably, this was soon after the structure of the alpha helix was suggested in 1951 by Linus Pauling and coworkers. These studies were published in the absence of knowledge of a keratin sequence. The first keratin sequences were determined by Hanukoglu and Fuchs in 1982.

...
Wikipedia