Spectrin structural domains. The α- and β-spectrin chains have sequential, triple helical “spectrin repeats,” numbered from the N-terminus of each chain.
There are nonrepeat segments, including the actin/protein 4.1 binding sites (Actin/4.1), a potential calcium-binding region (EF Hands), and a Src-homology
domain (SH3). Binding to ankyrin occurs at repeat 15 of the β chain (Ankyrin). The α and β chains align antiparallel to each other and form a heterodimer
by interacting at a “nucleation site” near one end of each chain. Two heterodimers associate to form a heterotetramer by interaction at “self-association
sites” at the C-terminus of the β chain and the N-terminus of the α chain. Each chain can be divided into large structural domains by limited tryptic
digestion, denoted as the αI to αV domains in the α chain and the βI to βIV domains in the β chain. For clarity, only a portion of the heterodimer on the right
Source: Hereditary Spherocytosis and Hereditary Elliptocytosis, The Online Metabolic and Molecular Bases of Inherited Disease
is shown.
Citation: Valle D, Beaudet AL, Vogelstein B, Kinzler KW, Antonarakis SE, Ballabio A, Gibson K, Mitchell G. The Online Metabolic and Molecular
Bases of Inherited Disease; 2014 Available at: http://mhmedical.com/ Accessed: July 31, 2017
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