Table 3. Primers used in this study.

Application	Primer sequence (5’ to 3’)
Amplification of last 641 bp of tolB	ATGACCATGATTACGCCAAGCTTTGACCTTCGAAAGCGGTCGT (fwr) TCCTCGCCCTTGCTCACCATagaaccaccaccaccCAGATACGGCGACCAGGCAG (rev)
Amplification of mCherry	CTGCCTGGTCGCCGTATCTGggtggtggtggttctATGGTGAGCAAGGGCGAGGA (fwr) CAGGGTAATATAATCTCCAGAGGCTACTTGTACAGCTCGTCCA (rev)
Amplification of spcR	ATGGACGAGCTGTACAAGTAGCCTCTGGAGATTATATTACCCTG (fwr) CCGGTGCTGTGACGACCTTCCGCACCAAGTGGACGATTATTAGGGATAACA (rev)
Amplification of 300 bp region downstream of tolB with the last 50 bp of the upstream fragment cloned at its 5’ end	TCGTCACAGCACCGGCGGCATGGACGAGCTGTACAAGTAGTAATAATTAATTGAATAGTA (fwr) AAACGACGGCCAGTGAATTCTCCAGCATTTGAGCGAAGTC (rev)
Amplification of GFP-t-tolA	GCAGCAGAATTCGTGTCAAAGGCAACCGAACA (fwr) GCAGCAGTCGACTTACGGTTTGAAGTCCAATG (rev)