A search of the Drosophila genome for gene products with similarities to th
e amino acid sequences of three tryptic peptides from locust (Schistocerca
gregaria) resilin gave two positive results: gene products CG15920 and CG90
36. In both conceptual translation products a 62-residue region is present,
which is identical to the resilin peptides in 29 positions. Gene product C
G15920 has an amino acid composition closely resembling that of resilins fr
om various insect species, and it has an N-terminal signal peptide sequence
indicating that it is an extracellular protein. The 62-residue region show
s similarity to the RR-2 sequence, which is common for a number of matrix p
roteins from insect solid cuticle. The N- and C-terminal regions flanking t
he 62-residue in CG 15920 are dominated by 18 repeats of a 15-residue seque
nce and I I repeats of a 13-residue sequence, respectively. The structures
of the repeats predict that the peptide chain will fold in an irregular, ex
tended beta-spiral, resembling the structures suggested for mammalian elast
in and spider flagelliform silk, two materials which, like resilin, possess
long-range elasticity. Accordingly, we suggest that gene product CG15920 i
s a Drosophila resilin precursor. (C) 2001 Elsevier Science Ltd. All rights
reserved.