To prepare the chimeras with SiBPs fused at
the C-terminus of the 6mer, pET30L-6mer was digested by SpeI
and then treated by antarctic phosphatase (NEB; MA) to prevent
self-ligation. The nucleotide sequences of SiBPs, A1 (SGSKGSKRRIL),
A3 (MSPHPHPRHHHT) and R5 (SSKKSGSYSGSKGSKRRIL) were
designed with restriction endonuclease sites NheI and SpeI flanked
at 50 and 30 terminals, respectively.