Table 1 Strains, cell lines, plasmids and primers used in this study

 DH5αMCR

endA1 supE44 thi-1 λ- recA1 gyrA96 relA1 deoR ∆(lacZYA-argF) U196 Ø80 ∆lacZ∆M15mcrA ∆ (mmrhsdRMS mcrBC)

[39]

 OP50

Uracil-auxotrophic E. coli B strain

[40]

 NCTC 12023

Wild-type identical to ATCC 14028

National Collection of Type Cultures (Colindale, UK)

 CDC-E8392

Wild-type, Biovar. mitis, tox⁺

[41]

 CAM-1

CDC-E8392 DIP0733::pCR2.1 TOPODIP0733’

[14]

 INCA 402

Isolate from a patient with pneumonia, biovar. Belfanti, tox⁻

[41]

 ATCC 13032

Type strain, non-pathogenic

[42]

 Detroit562

Human hypopharyngeal carcinoma cells (ATCC CCL-2)

[43]

 HeLa

Human cervical carcinoma cells

(ATCC CCL-2)

[44, 45]

 pXMJ19

ori colE1, oriCg, ptac, Cm^R

[46]

 pXMJ19_DIP0733

ori colE1, oriCg, ptac, CDCE8392_0678, Cm^R

[14]

 pXMJ19_DIP0733-cc

pXMJ19 with 2700 bp insert of 3′-shortened CDCE8392_0678 (DIP0733 homolog without sequence for C-terminal disorder- and coiled-coil-region) from C. diphtheriae CDC-E8392

This study

 pXMJ19_Cg0896

ori colE1, oriCg, ptac, Cg0896, Cm^R

 pXMJ19_Cg0896 + cc

pXMJ19 with 2693 bp insert of 3′-shortened Cg0896 (DIP0733 homolog without sequence for C-terminal disorder- and coiled-coil-region) from C. glutamicum ATCC 130323 and 268 bp insert of 5`-shortened CDB402_0643 (DIP0733 homolog sequence for C-terminal disorder- and coiled-coil-region) from C. diphtheriae INCA-402

 Probe 16SrRNA

GCAGCCGCGGTAATACGTAG

This study

GGGCCCTAATACGACTCACTATAGGGACATCTCACGACACGAGCTG

 Probe DIP0733

CGACCCAGTGCTTAAGGCAT

GGGCCCTAATACGACTCACTATACCTGTGCCTGCTTTGGACCC

 Probe Cg0896

GTACGACGGAACTGTTGAAC

GGGCCCTAATACGACTCACTATAGCCTGCTTTGGACCCTGGGTC

 pXMJ19_DIP0733-cc

CGCGCCTGCAGGTTGGCGACCGGTTTTACGCG

CGCGCCCGGGTTACTTAGGGTCAATACCTACCT

 pXMJ19_Cg0896

CGCGCCTGCAGGTTGTCGACTGGTCTCACACC

CGCGCCCGGGCTACTGTGCGGACTGGTAGC

 pXMJ19_Cg0896 + cc

CGCGCCTGCAGGTTGTCGACTGGTCTCACACC

CGCGCCTTAGGCTGCGATAGGGCTTCAG