Fig. 3.

Circular constructs made in this study. a Schematic representation of the PCR-based engineering of the constructs used for the intein-based circularization of LicA. NcoI and XhoI are the introduced restriction sites. The amino acid sequence of the overlap of the PCR-1 fragments is shown. b, c Amino acid sequences of the N- and C-terminal regions of linear (b) and circular (c) variants of LicA. The extein sequences, corresponding to the wild-type sequence, are underlined. Note that in all constructs, the signal sequence has been deleted, resulting in intracellular production of the proteins. The length of the loops is given as well as the specific activity of the purified proteins (in units per milligram). Asterisk indicates the connection point of the N- and C-terminal sequence