Alpha solenoid

An example of an alpha solenoid structure composed of 15 HEAT repeats. The protein phosphatase 2A regulatory subunit is shown with the N-terminus in blue at bottom and the C-terminus in red at top. A single helix-turn-helix motif is shown in the center with the outer helix in pink, the inner helix in green, and the turn in white. From PDB: 2IAE​.[1]

An alpha solenoid (sometimes also known as an alpha horseshoe or as stacked pairs of alpha helices, abbreviated SPAH) is a protein fold composed of repeating alpha helix subunits, commonly helix-turn-helix motifs, arranged in antiparallel fashion to form a superhelix.[2] Alpha solenoids are known for their flexibility and plasticity.[3] Like beta propellers, alpha solenoids are a form of solenoid protein domain commonly found in the proteins comprising the nuclear pore complex.[4] They are also common in membrane coat proteins known as coatomers, such as clathrin, and in regulatory proteins that form extensive protein-protein interactions with their binding partners.[2][4] Examples of alpha solenoid structures binding RNA and lipids have also been described.[2]

  1. ^ Cho, Uhn Soo; Xu, Wenqing (1 November 2006). "Crystal structure of a protein phosphatase 2A heterotrimeric holoenzyme". Nature. 445 (7123): 53–57. doi:10.1038/nature05351. PMID 17086192. S2CID 4408160.
  2. ^ a b c Fournier, David; Palidwor, Gareth A.; Shcherbinin, Sergey; Szengel, Angelika; Schaefer, Martin H.; Perez-Iratxeta, Carol; Andrade-Navarro, Miguel A.; E. Tosatto, Silvio C. (21 November 2013). "Functional and Genomic Analyses of Alpha-Solenoid Proteins". PLOS ONE. 8 (11): e79894. Bibcode:2013PLoSO...879894F. doi:10.1371/journal.pone.0079894. PMC 3837014. PMID 24278209.
  3. ^ Kappel, Christian; Zachariae, Ulrich; Dölker, Nicole; Grubmüller, Helmut (September 2010). "An Unusual Hydrophobic Core Confers Extreme Flexibility to HEAT Repeat Proteins". Biophysical Journal. 99 (5): 1596–1603. Bibcode:2010BpJ....99.1596K. doi:10.1016/j.bpj.2010.06.032. PMC 2931736. PMID 20816072.
  4. ^ a b Field, Mark C.; Sali, Andrej; Rout, Michael P. (13 June 2011). "On a bender—BARs, ESCRTs, COPs, and finally getting your coat". The Journal of Cell Biology. 193 (6): 963–972. doi:10.1083/jcb.201102042. PMC 3115789. PMID 21670211.