With the publication of the complete Tannerella forsythensis genome we are reminded of the prominence of conjugative transposons in Bacteroides. BLAST protein comparisons of published sequences for CTn341 and CTnDOT reveals conjugative transposon segments in each of T.forsythensis, P.intermedia and P.gingivalis. See the attached table. In all three cases, predicted genomic islands correspond to the tra region of genes; in Tannerella, the island may also extend to cover the int-exc-tetQ-rte stretch. The Tannerella segment at TF2220-TF2267 is the most complete and shows the most synteny and the highest similarity to the CTn341, while the 10 genes and 3 gene fragments matching CTn341 genes clustered between TF0851 and TF0927 have neither synteny nor high similarity to the CTn341 genes.

In light of the significance of these transposon genes for the Bacteroides, we have appended the CTn341 and CTnDOT coding sequences to the Tannerella database; see CTNBV1 -- CTNBV39 and CTNDOT1 -- CTNDOT33. Also, records TF2220 -- TF2267, PI0216 -- PI0268 and PG1309 -- PG1287 have been updated. We append below a list of relevant references for Bacteroides conjugative transposons (if we have overlooked any reference, we will be quick to correct that when notified).

Bacteroides Conjugative Transposons Table

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1: Moon K, Shoemaker NB, Gardner JF, Salyers AA.
Regulation of excision genes of the Bacteroides conjugative transposon CTnDOT.
J Bacteriol. 2005 Aug;187(16):5732-41.
PMID: 16077120

2: DiChiara JM, Salyers AA, Gardner JF.
In vitro analysis of sequence requirements for the excision reaction of the
Bactroides conjugative transposon, CTnDOT.
Mol Microbiol. 2005 May;56(4):1035-48.
PMID: 15853888

3: Bacic M, Parker AC, Stagg J, Whitley HP, Wells WG, Jacob LA, Smith CJ.
Genetic and structural analysis of the Bacteroides conjugative transposon
CTn341.
J Bacteriol. 2005 Apr;187(8):2858-69.
PMID: 15805532

4: Wang Y, Rotman ER, Shoemaker NB, Salyers AA.
Translational control of tetracycline resistance and conjugation in the
Bactroides conjugative transposon CTnDOT.
J Bacteriol. 2005 Apr;187(8):2673-80.
PMID: 15805513

1:  Franco AA.
The Bacteroides fragilis pathogenicity island is contained in a putative novel
conjugative transposon.
J Bacteriol. 2004 Sep;186(18):6077-92.
PMID: 15342577

2: Sutanto Y, DiChiara JM, Shoemaker NB, Gardner JF, Salyers AA.
Factors required in vitro for excision of the Bacteroides conjugative
transposon, CTnDOT.
Plasmid. 2004 Sep;52(2):119-30.
PMID: 15336489

3: Wang Y, Shoemaker NB, Salyers AA.
Regulation of a Bacteroides operon that controls excision and transfer of the
conjugative transposon CTnDOT.
J Bacteriol. 2004 May;186(9):2548-57.
PMID: 15090494

1:  Gupta A, Vlamakis H, Shoemaker N, Salyers AA.
A new Bacteroides conjugative transposon that carries an ermB gene.
Appl Environ Microbiol. 2003 Nov;69(11):6455-63.
PMID: 14602600

2: Wang Y, Wang GR, Shelby A, Shoemaker NB, Salyers AA.
A newly discovered Bacteroides conjugative transposon, CTnGERM1, contains genes
also found in gram-positive bacteria.
Appl Environ Microbiol. 2003 Aug;69(8):4595-603.
PMID: 12902247

1:  Whittle G, Shoemaker NB, Salyers AA.
The role of Bacteroides conjugative transposons in the dissemination of
antibiotic resistance genes.
Cell Mol Life Sci. 2002 Dec;59(12):2044-54.
PMID: 12568330

2: Osborn AM, Boltner D.
When phage, plasmids, and transposons collide: genomic islands, and
conjugative- and mobilizable-transposons as a mosaic continuum.
Plasmid. 2002 Nov;48(3):202-12.
PMID: 12460536

3: Sutanto Y, Shoemaker NB, Gardner JF, Salyers AA.
Characterization of Exc, a novel protein required for the excision of
Bactroides conjugative transposon.
Mol Microbiol. 2002 Dec;46(5):1239-46.
PMID: 12453211

4: Cheng Q, Wesslund N, Shoemaker NB, Salyers AA, Gardner JF.
Development of an in vitro integration assay for the Bacteroides conjugative
transposon CTnDOT.
J Bacteriol. 2002 Sep;184(17):4829-37.
PMID: 12169608

5: Whittle G, Shoemaker NB, Salyers AA.
Characterization of genes involved in modulation of conjugal transfer of the
Bactroides conjugative transposon CTnDOT.
J Bacteriol. 2002 Jul;184(14):3839-47.
PMID: 12081954

6: Bass KA, Hecht DW.
Isolation and characterization of cLV25, a Bacteroides fragilis chromosomal
transfer factor resembling multiple Bacteroides sp. mobilizable transposons.
J Bacteriol. 2002 Apr;184(7):1895-904.
PMID: 11889096

1:  Bonheyo GT, Hund BD, Shoemaker NB, Salyers AA. 
Transfer region of a Bacteroides conjugative transposon contains regulatory as
well as structural genes.
Plasmid. 2001 Nov;46(3):202-9. 
PMID: 11735369 

2: Smith CJ, Parker AC, Bacic M. 
Analysis of a Bacteroides conjugative transposon using a novel "targeted
capture" model system.
Plasmid. 2001 Jul;46(1):47-56. 
PMID: 11535035 

3: Cheng Q, Sutanto Y, Shoemaker NB, Gardner JF, Salyers AA. 
Identification of genes required for excision of CTnDOT, a Bacteroides
conjugative transposon.
Mol Microbiol. 2001 Aug;41(3):625-32. 
PMID: 11532130 

4: Whittle G, Hund BD, Shoemaker NB, Salyers AA. 
Characterization of the 13-kilobase ermF region of the Bacteroides conjugative
transposon CTnDOT.
Appl Environ Microbiol. 2001 Aug;67(8):3488-95. 
PMID: 11472924 

5: Bonheyo G, Graham D, Shoemaker NB, Salyers AA. 
Transfer region of a bacteroides conjugative transposon, CTnDOT.
Plasmid. 2001 Jan;45(1):41-51. 
PMID: 11319931 

6: Shoemaker NB, Vlamakis H, Hayes K, Salyers AA. 
Evidence for extensive resistance gene transfer among Bacteroides spp. and
among Bacteroides and other genera in the human colon.
Appl Environ Microbiol. 2001 Feb;67(2):561-8. 
PMID: 11157217 

Cheng Q, Paszkiet BJ, Shoemaker NB, Gardner JF, Salyers AA.
Integration and excision of a Bacteroides conjugative transposon, CTnDOT.
J Bacteriol. 2000 Jul;182(14):4035-43.
PMID: 10869083