The zinc metalloproteinases are involved in virulence and possess antigenic properties [42]. AP200 carries three of them, iga, zmpB and

zmpC, lacking zmpD. Mobile genetic elements of AP200 Tn1806 The Tn1806 transposon represents the sole erm(TR)-carrying genetic element reported in S. pneumoniae to date, and only a partial sequence was published by our group in 2008 [22]. Tn1806 is 52,457 bp selleck in size, smaller than the size previously estimated by PCR mapping [22], has a GC content of 31.1%, and comprises 49 ORFs. The chromosomal insertion site (hsdM gene) of Tn1806 is characterized by the duplication of 3 nucleotides (GGG) representing the target sequence for the integration [22]. Although various proteins related to mobilization are present, such as a TraG/TraD protein, a Type IV secretory protein, a relaxase and 3 recombinases at the right end (Figure 3 and Additional file 2), conjugation experiments have failed to show transferability of Tn1806 selleck products to other strains [22]. Other putative antibiotic resistance genes are present in Tn1806 in the region flanking erm(TR), such as the two components of a tetronasin ABC-type efflux system and a spectinomycin phosphotransferase. A TetR family transcriptional regulator is located upstream of the tetronasin efflux

system, likely being involved in its regulation [43, 44]. Figure 3 Schematic representation of Tn 1806 of S. pneumoniae AP200, in comparison with Androgen Receptor Antagonist libraries ICE10750 RD-2 of S. pyogenes. The erm(TR) gene is indicated by a red arrow. Blue arrows indicate shared ORFs between the 2 elements. Yellow arrows indicate the ORFs uniquely present in Tn1806 while green arrows indicate those uniquely present in ICE10750 RD-2. Shaded areas between the elements Buspirone HCl indicate a nucleotide identity greater than 90%. The proteins of Tn1806 indicated in the figure are described in the text. Tn1806 shows an overall similarity with the erm(TR)-carrying genetic element described in Streptococcus

pyogenes MGAS10750, named ICE10750 RD-2 [45]. ICE, Integrative and Conjugative Element, identifies a new classification nomenclature, grouping self-transmissible genetic elements previously designated as transposons, conjugative transposons, genomic islands and plasmids, sharing a common mechanism of horizontal transfer via site-specific recombination [46]. In this broad definition, also Tn1806 can be considered an ICE. Tn1806 is approximately 4 kb larger than ICE 10750-RD.2 due to the presence of additional regions (Figure 3). Starting from the 5′ end of the element, Tn1806 contains 3 additional ORFs homologous to hypothetical proteins of the chimeric element RD1 of S. pyogenes MGAS6180 [47], 2 ORFs homologous to hypothetical proteins contained in the plasmid pAPRE01 of Anaerococcus prevotii DSM20548, and a retron-type reverse transcriptase inserted inside the adenine-specific DNA methylase gene.