Table 1. Primers used for construction of plasmids.

Oligonucleotide	Primer
WT-NdeI-N	CGCGGCATATGTTTGATTTACTCCTGC
WT-XhoI-C	TCGCACTCGAGAAAATCGAAGGCATGT
H59A-N	GGCATCGACCCCGCTACCCACATGCAGTTGCCC
H59A-C	CAACTGCATGTGGGTAGCGGGGTCGATGCCGCC
H61A-N	GACCCCCATACCGCCATGCAGTTGCCCTTCATG
H61A-C	GAAGGGCAACTGCATGGCGGTATGGGGGTCGAT
H183A-N	GCGGTGCCGACGGTGGCCGCGGAGAACGGCGAA
H183A-C	GCCGTTCTCCGCGGCCACCGTCGGCACCGCGCC
H239A-N	CTGTACCTGGTAGCTATTTCCAGCCGCGAGGCG
H239A-C	CTCGCGGCTGGAAATAGCTACCAGGTACAGCGG
K150A-N	GTGAACAGCTTCGCGCACTTCATGGCCTACAAG
K150A-C	GTAGGCCATGAAGTGCGCGAAGCTGTTCACCCC
D316A-N	ACCACCGCCACCGCCCACTGCTGCTTCTGCGCC
D316A-C	GCAGAAGCAGCAGTGGGCGGTGGCGGTGGTATG
Y155A-N	CACTTCATGGCCGCCAAGAACGCCATCATGGCC
Y155A-C	CATGATGGCGTTCTTGGCGGCCATGAAGTGCTT
S289A-N	GGCTACGTGATGGCCCCGCCGTTCCGTCCCGTC
S289A-C	GGGACGGAACGGCGGGGCCATCACGTAGCCGGC
N337A-N	TTCAGCAAGATTCCCGCTGGCACGGCCGGCATC
N337A-C	GCCGGCCGTGCCAGCGGGAATCTTGCTGAAGTC

These plasmids were verified by DNA sequencing. Underlined nucleotides indicate the designated site for mutation or the restriction site.