Another possibility is that there are other, as yet

unannotated proteins that play a role in a putative flagellar system in C. pneumoniae. For example, along with the FliH/FliI complex that is formed in other bacteria, another protein, FliJ, which is a general chaperone, is believed to be involved in this complex [39, 44]. FliJ has not been identified in C. pneumoniae. In the absence of a genetic manipulation system for the chlamydiae, direct evidence for the role of these flagellar proteins remains elusive. The fact that FliI is enzymatically active and forms complexes in vitro with other flagellar proteins, all of which are present in all other chlamydiae sps. studied to date, suggests that these proteins play an important role in chlamydial replication or survival. Further see more studies using heterologous systems and genetic complementation could help to decipher the exact role of these flagellar proteins in chlamydiae. Methods Expression Plasmids C. pneumoniae CWL029 (VR1310:ATCC) (GenBank accession # AE001363) was the strain used to isolate genomic DNA for cloning and protein expression. Full length fliI, Cpn0859, cdsL, copN, Cpn0322, and fragments of flhA, fliF, and fliI were amplified from CWL029 using AttB-containing primers (Gateway; Invitrogen).

The amplified products were cloned into pDONR201 (Gateway; Invitrogen) to generate pENT vectors. The pENT vectors were then Ro 61-8048 research buy used in LR reactions (Gateway; Invitrogen) to produce pEX vectors containing the genes of interest. We used either pEX17 (N terminal His tag) or pEX15 (N terminal GST tag) vectors for our protein expression. All constructs were confirmed by sequencing at the Molecular Biology Facility at McMaster University. To identify protein interactions we utilized the bacterial-2-hybrid Exoribonuclease system [39]. Genes of interest were

cloned into either pT18 or pT25 plasmids, each of which expresses a different fragment of adenylate cyclase. When these two plasmids are co-transformed, expressing the protein of interest fused to the adenylate cyclase fragment, any interaction between the two proteins results in production of cAMP. Increases in cAMP results in an increase in the β-galactosidase gene that can be monitored using β-galactosidase activity assays. pT18 and pT25 were digested with KpnI (New England Biolabs) as well as genes amplified from CWL029 (fliI, flhA, fliF, cdsL, Cpn0322, copN) that had a KpnI site designed into the primers. Ligation was performed overnight at 16°C using T4 Ligase (Invitrogen) and the resulting mixture was used to transform E. coli XL-1 cells and transformants were selected on 100 μg/μL ampicillin and 34 μg/μL chloramphenicol (Luria Bertani) LB plates. Plasmids were prepared using the GenElute Plasmid Miniprep Kit (Sigma). Protein Expression All constructs were expressed in E. coli Rosetta pLysS. Expression plasmids were used to transform E.