1. YAN, Y., WINOGRAD, E., VIEL, A., CRONIN, T., HARRISON, S.C.
AND BRANTON, D.
Crystal structure of the repetitive segments of spectrin.
SCIENCE 262 2027-2030 (1993).
2. SPEICHER, D.W. AND MARCHESI, V.T.
Erythrocyte spectrin is comprised of many homologous triple helical
NATURE 311 177-180 (1984).
3. SPEICHER, D.W., WEGLARZ, L. AND DESILVA, T.M.
Properties of human red cell spectrin heterodimer (side-to-side)
assembly and identification of an essential nucleation site.
J.BIOL.CHEM. 267 14775-14782 (1992).
4. PASCUAL, J., PFUHL, M., WALTHER, D., SARASTE, M. AND NILGES, M.
Solution structure of the spectrin repeat: a left-handed antiparallel
J.MOL.BIOL. 273 740-751 (1997).
5. MAILLET, P., ALLOISIO, N., MORLE, L. AND DELAUNAY, J.
Spectrin mutations in hereditary elliptocytosis and hereditary
HUM.MUTAT. 8 97-107 (1996).
6. FLOYD, P.B., GALLAGHER, P.G., VALENTINO, L.A., DAVIS, M.,
MARCHESI, S.L. AND FORGET, B.G.
Heterogeneity of the molecular basis of hereditary pyropoikilocytosis
and hereditary elliptocytosis associated with increased levels of the
spectrin alpha I/74-kilodalton tryptic peptide.
BLOOD 78 1364-1372 (1991).
Spectrin is an elongated protein that belongs to a family of related
molecules (including dystrophin and alpha-actinin) that contain tandemly
repeated segments and form resilient cellular meshworks by cross-linking
actin filaments . The protein is an alpha-beta heterodimer  in which
the alpha and beta monomers associate in an anti-parallel fashion .
Assembly involves initial contact of complementary nucleation sites on each
subunit, via four tandem repeat regions . Following nucleation, the
remainder of the subunits associate rapidly along their full lengths to
form a dimer by super-coiling around each other, forming a rope-like,
flexible rod . Assembly terminates if either polypeptide is interrupted
by protease cleavage. Heterozygotic mutations involving either nucleation
site are predicted to affect allele incorporation into the mature membrane
The structure of a repeat unit of alpha-spectrin has been determined to
1.8A resolution by means of X-ray crystallography . This was shown to
comprise an anti-parallel three-helix bundle separated by two loops, which
folds into a left-handed coiled coil . At the interface between tandem
repeats, hydrophobic interactions may constrain intersegment flexibility.
The interaction between alpha- and beta-subunits is mediated by the
association of two helices at the C-terminus of the beta-chain and a single
helix from the N-terminus of the alpha-chain. Mutations that affect these
critical helix side-chain interactions disrupt spectrin associations that
sustain the integrity of erythrocyte membranes giving rise to haemolytic
anaemias [1,4]. These haemolytic syndromes include hereditary ellipto-
cytosis, its aggravated form hereditary pyropoikilocytosis and hereditary
SPECTRNALPHA is a 3-element fingerprint that provides a signature for
spectrin alpha chains. The fingerprint was derived from an initial
alignment of 10 sequences: the motifs were drawn from the SH3 domain
in central portion of the alignment, focusing on those sections that
characterise the alpha spectrin SH3 domains and distinguish them from
other closely-related SH3-domain containing proteins. A single
iteration on SPTR44_27f was required to reach convergence, no further
sequences being identified beyond the starting set.
An update on SPTR55_38f identified a true set comprising 25 sequences.
A0JPA2_XENTR LOC100036647 protein - Xenopus tropicalis (Western clawed frog) (Silurana tropicalis).
A3FG33_DANRE Alpha II-spectrin - Danio rerio (Zebrafish) (Brachydanio rerio).
A3KGU5_MOUSE Spectrin alpha 2 - Mus musculus (Mouse).
A3KGU7_MOUSE Spectrin alpha 2 - Mus musculus (Mouse).
A3KGU8_MOUSE Spectrin alpha 2 - Mus musculus (Mouse).
A6NG51_HUMAN Uncharacterized protein SPTAN1 - Homo sapiens (Human).
A8PJH9_BRUMA Spectrin alpha chain, putative - Brugia malayi (Filarial nematode worm).
A8XJE3_CAEBR Putative uncharacterized protein - Caenorhabditis briggsae.
Q16EQ1_AEDAE Spectrin - Aedes aegypti (Yellowfever mosquito).
Q21408 Spectrin protein 1 - Caenorhabditis elegans.
Q3KN50_DROME RE03775p - Drosophila melanogaster (Fruit fly).
Q4T9R4_TETNG Chromosome undetermined SCAF7505, whole genome shotgun sequence - Tetraodon nigroviridis (Green puffer).
Q4T9R5_TETNG Chromosome undetermined SCAF7505, whole genome shotgun sequence - Tetraodon nigroviridis (Green puffer).
Q5VYL1_HUMAN Spectrin, alpha, erythrocytic 1 (Elliptocytosis 2) - Homo sapiens (Human).
Q5VYL2_HUMAN Spectrin, alpha, erythrocytic 1 (Elliptocytosis 2) - Homo sapiens (Human).
Q6IRK8 Spna2 protein - Rattus norvegicus (Rat).
Q6XDA1 Erythroid spectrin alpha - Rattus norvegicus (Rat).
Q7Q515_ANOGA AGAP006686-PA - Anopheles gambiae str. PEST.
SPCA_DROME Spectrin alpha chain - Drosophila melanogaster (Fruit fly).
SPCA_HUMAN Spectrin alpha chain, erythrocyte (Erythroid alpha-spectrin) - Homo sapiens (Human).
SPCA_MOUSE Spectrin alpha chain, erythrocyte (Erythroid alpha-spectrin) - Mus musculus (Mouse).
SPCN_CHICK Spectrin alpha chain, brain (Spectrin, non-erythroid alpha chain) (Fodrin alpha chain) - Gallus gallus (Chicken).
SPCN_HUMAN Spectrin alpha chain, brain (Spectrin, non-erythroid alpha chain) (Alpha-II spectrin) (Fodrin alpha chain) - Homo sapiens (Human).
SPCN_RAT Spectrin alpha chain, brain (Spectrin, non-erythroid alpha chain) (Alpha-II spectrin) (Fodrin alpha chain) - Rattus norvegicus (Rat).
SPTA2_MOUSE Spectrin alpha chain, brain (Spectrin, non-erythroid alpha chain) (Alpha-II spectrin) (Fodrin alpha chain) - Mus musculus (Mouse).