Fig. 2.
Expression of spider dragline silk proteins in metabolically engineered Escherichia coli. Coomassie-stained 10% SDS-PAGE gel analysis of lysates of E. coli BL21(DE3) cells cotransformed with a silk expression plasmid indicated at the right and a compatible plasmid for each lane. Lane 1, pACYC184 as control; lane 2, pTetglyVXY for overexpression of glyVXY that encode tRNAGly; lane 3, pTetgly2 containing two glyVXY expression cassettes; lane 4, p184glyAn for glyA overexpression to increase glycine pool; lane 5, either pTetgly-glyAn (for 32-, 48-, and 64-mer) or pTetgly2-glyAn (for 80- and 96-mer) that allow glyVXY and glyA overexpression simultaneously.