Spidroin
Spidroin, the major protein of spider dragline silk, is typical of fibrous proteins in having a highly repetitive structure, represented here only by a fragment. It has been suggested that the entire sequence exists of alternating repetitive and non-repetitive segments similar to those seen in the sequence below.
Spidroin
Dragline Silk Fibroin 1 (Fragment)
Nephila clavipes
( ) =13-residue theme AGQGGYGGLGGQG
[ ] = second theme AGRGGLGGQGAGA...
{ } = nonrepetitive region
(AGQGGYGGLGGQG)
(AGQGGYGGLGGQG)
[AGQGAGAAAAAAAGG]
(AGQGGYGGLGSQG)
[AGRGGQGAGAAAAAAGG]
(AGQGGYGGLGSQG)
[AGRGGLGGQGAGAAAAAAAGG]
(AGQGGYGGLGNQG)
[AGRGGQGAAAAAAGG]
(AGQGGYGGLGSQG)
[AGRGGLGGQGAGAAAAAAGG]
(AGQGGYGGLGGQG)
(AGQGGYGGLGSQG)
[AGRGGLGGQGAGAAAAAAAGGAGQGGLGGQGAGQGAGASAAAAGG]
(AGQGGYGGLGSQG)
[AGRGGEGAGAAAAAAGG]
(AGQGGYGGLGGQG)
(AGQGGYGGLGSQG)
[AGRGGLGGQGAGAAAAGGAGQGGLGGQGAGQGAGAAAAAAGG]
(AGQGGYGGLGSQG)
[AGRGGLGGQGAGAVAAAAAGG]
(AGQGGYGG-GSQG)
[AGRGGQGAGAAAAAAGG]
(AGQRGYGGLGNQG)
[AGRGGLGGQGAGAAAAAAAGG]
(AGQGGYGGLGNQG)
[AGRGGQGAAAAAGG]
(AGQGGYGGLGSQG) [AGRGGQGAGAAAAAAVGAGQEGIRGQG]
(AGQGGYGGLGSQG)
[SGRGGLGGQGAGAAAAAAGGAGQGGLGGQGAGQGAGAAAAAAGG]
(VRQGGYGGLGSQG)
[AGRGGQGAGAAAAAAGG]
(AGQGGYGGLGGQG)
[VGRGGLGGQGAGAAAAGG]
(AGQGGYGGVGSGA)
{SAASAAASRLSSPQASSRVSSAVSNLVASGPTNSAALSSTISNVVSQIGASN
PGLSGCDVLIQALLEVVSALIQILGSSSIGQVNYGSAGQATQIVGQSVYQAL}Links to the music
Spidroin I
Spidroin II
Notes on the music:
The repetitive section consists of two alternating themes, a 13-residue theme which is largely invariant, and a second theme, which appears more improvisational, with variation in both its length and amino acid composition. Click here to hear the 13-residue theme. Both themes are characterized by a return to the amino acid glycine every two or three residues. The repetition of the glycine note in the sequence adds a curious programmatic touch to the music, like the rapid cycling of notes that accompany other "spinning songs."