TABLE 1.

Oligonucleotide primers used in this study

Primer	Sequence (5′ to 3′)	Locationa
B1	GGATCCACAGCTTCCGGTTTAATAGGTGTA	−475
B2	GGATCCAGGCCACTCTTAGTCTGCTTACAT	3659
B3	TCGGTTTTTTGATTGGTTTTTCAGTATTAG	1596
B4	AAAACCAATCAAAAAACCGAATAAACCAATC	3280
A1	GATCAGATTCAAGGTGGACAGC	625
A2	CTGCTCAAAAGGTTTGGGAAGG	1307
16S-1	CCTATAAGACTGGGATAACTTCGGG	119
16S-2	CTTTGAGTTTCAACCTTGCGGTCG	910

^aLocations of cna primers are relative to the ATG start codon; locations of 16S rRNA gene primers are based on GenBank accession no. X68417. Orientations of the B2 and B3 primers are opposite those of the B1, B4, A1, and A1 primers. The underlined bases in the B2 primer define a BamHI site that was added to facilitate cloning; the given location of 3659 corresponds to the adenine adjacent to this BamHI site. Given their opposite orientations, the boldfaced bases in the B3 and B4 primers are complementary to each other. Double underlines indicate bases on the opposite end of the B domains. More directly, the first 10 bases in the B3 primer correspond to the 5′ end of the W domain, with position 1596 corresponding to the last base at the 3′ end of the A domain. Similarly, the first 10 bases in the B4 primer correspond to the 3′ end of the A domain, with position 3280 corresponding to the 5′ end of the W domain.