Editing Calmodulin (section)

=== Importance of flexibility in calmodulin ===
Calmodulin's ability to recognize a tremendous range of target proteins is due in large part to its structural flexibility.<ref>{{cite journal | vauthors = Yamniuk AP, Vogel HJ | s2cid = 26585744 | title = Calmodulin's flexibility allows for promiscuity in its interactions with target proteins and peptides | journal = Molecular Biotechnology | volume = 27 | issue = 1 | pages = 33–57 | date = May 2004 | pmid = 15122046 | doi = 10.1385/MB:27:1:33 }}</ref>  In addition to the flexibility of the central linker domain, the N- and C-domains undergo open-closed conformational cycling in the Ca<sup>2+</sup>-bound state.<ref name="CYhOa" />  Calmodulin also exhibits great structural variability, and undergoes considerable conformational fluctuations, when bound to targets.<ref name="Tidow_2013">{{cite journal | vauthors = Tidow H, Nissen P | title = Structural diversity of calmodulin binding to its target sites | journal = The FEBS Journal | volume = 280 | issue = 21 | pages = 5551–65 | date = November 2013 | pmid = 23601118 | doi = 10.1111/febs.12296 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Frederick KK, Marlow MS, Valentine KG, Wand AJ | title = Conformational entropy in molecular recognition by proteins | journal = Nature | volume = 448 | issue = 7151 | pages = 325–9 | date = July 2007 | pmid = 17637663 | doi = 10.1038/nature05959 | pmc = 4156320 | bibcode = 2007Natur.448..325F }}</ref><ref>{{cite journal | vauthors = Gsponer J, Christodoulou J, Cavalli A, Bui JM, Richter B, Dobson CM, Vendruscolo M | title = A coupled equilibrium shift mechanism in calmodulin-mediated signal transduction | journal = Structure | volume = 16 | issue = 5 | pages = 736–46 | date = May 2008 | pmid = 18462678 | doi = 10.1016/j.str.2008.02.017 | pmc = 2428103 }}</ref> Moreover, the predominantly hydrophobic nature of binding between calmodulin and most of its targets allows for recognition of a broad range of target protein sequences.<ref name="Tidow_2013" /><ref>{{cite journal | vauthors = Ishida H, Vogel HJ | title = Protein-peptide interaction studies demonstrate the versatility of calmodulin target protein binding | journal = Protein and Peptide Letters | volume = 13 | issue = 5 | pages = 455–65 | date = 2006 | pmid = 16800798 | doi = 10.2174/092986606776819600 }}</ref>  Together, these features allow calmodulin to recognize some 300 target proteins<ref name="vCsmX">{{cite web |title=Calmodulin Target Database |url=http://calcium.uhnres.utoronto.ca/ctdb/ |access-date=27 July 2020 |archive-date=31 January 2023 |archive-url=https://web.archive.org/web/20230131125456/http://calcium.uhnres.utoronto.ca/ctdb/ |url-status=dead }}</ref> exhibiting a variety of CaM-binding sequence motifs.