components: 10 ng of the donor and recipient plasmids, 20 nM of
each forward and reverse primer, 200 lM of each dNTP, 1 Phusion
buffer and 1.6 U of Phusion DNA polymerase (Finnzymes,
Espoo, Finland). TPCR reactions for the mutagenesis protocol were
the same as for DNA cloning except that a single plasmid harboring
the target gene subjected to mutagenesis was used at 20 ng per
reaction and the mutagenic-primers (7 and 3 for CaM and Gb1,
respectively) were each added at 20 nM. If alternative primer concentrations
were used, this is noted in the text. Following completion
of the TPCR reactions, 1 ll of 20U/ll DpnI was added to 10 ll
of each of the TPCR reactions followed by incubation for 1–2 h at
37 C. The DNA was then directly transformed into highly-efficient
competent E. coli DH5a cells prepared as previously described
(Inoue et al., 1990).