TABLE 2.

Sequences of oligonucleotide primers used in this study

Primer	Sequencec	Positiona	Tmb (°C)
CM1	CTGCAGGCTACATTCTGGG	569-587	58.8
CM2	GTAAAGTCCTCTGCACCCCA	833-814	59.4
CM5	GGATATATCATATGTCAACGCTGAAGAATAC	1-20	62.9
CM6	CTATTAACAGAATTCGCCTTGAC	599-577d	57.1
CM7	CCACCACGATTTTCTGTGGTGCCCGAGAC	1053-1081	78.0e
CM8	GTCTCGGGCACCACAGAAAATCGTGGTGG	1081-1053	78.0e

^aPosition in the sequence of tibC of ETEC H10407, accession no. AF131891, except where indicated otherwise.

^bT_m, melting temperature. Values were provided by the manufacturer.

^cNucleotides in boldface are not complementary to the template DNA. Nucleotides corresponding to NdeI (CM5) and EcoRI (CM6) restriction sites are underlined.

^dPosition in the sequence of tibA of ETEC H10407, accession no. AF109215.

^eCalculated as described in the QuickChange site-directed mutagenesis kit.