Tentative identification of a resilin gene in Drosophila melanogaster

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.