RRC ID 36329
Author Gupta AK, Mita K, Arunkumar KP, Nagaraju J.
Title Molecular architecture of silk fibroin of Indian golden silkmoth, Antheraea assama.
Journal Sci Rep
Abstract The golden silk spun by Indian golden silkmoth Antheraea assama, is regarded for its shimmering golden luster, tenacity and value as biomaterial. This report describes the gene coding for golden silk H-fibroin (AaFhc), its expression, full-length sequence and structurally important motifs discerning the underlying genetic and biochemical factors responsible for its much sought-after properties. The coding region, with biased isocodons, encodes highly repetitious crystalline core, flanked by a pair of 5' and 3' non-repetitious ends. AaFhc mRNA expression is strictly territorial, confined to the posterior silk gland, encoding a protein of size 230 kDa, which makes homodimers making the elementary structural units of the fibrous core of the golden silk. Characteristic polyalanine repeats that make tight β-sheet crystals alternate with non-polyalanine repeats that make less orderly antiparallel β-sheets, β-turns and partial α-helices. Phylogenetic analysis of the conserved N-terminal amorphous motif and the comparative analysis of the crystalline region with other saturniid H-fibroins reveal that AaFhc has longer, numerous and relatively uniform repeat motifs with lower serine content that assume tighter β-crystals and denser packing, which are speculated to be responsible for its acclaimed properties of higher tensile strength and higher refractive index responsible for golden luster.
Volume 5
Pages 12706
Published 2015-8-3
DOI 10.1038/srep12706
PII srep12706
PMID 26235912
PMC PMC4522600
MeSH Amino Acid Motifs Animals Base Sequence Fibroins / chemistry Fibroins / genetics* Fibroins / metabolism Genes Insect Proteins / chemistry Insect Proteins / genetics* Insect Proteins / metabolism Molecular Sequence Data Moths / genetics* Moths / metabolism Phylogeny Sequence Alignment
IF 3.998