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Table 1 Interaction between the flagellar proteins of C. pneumoniae using the Bacterial-2-hybrid System

From: Interactions between flagellar and type III secretion proteins in Chlamydia pneumoniae

Plasmids β-Galactosidase Activity in units/mg bacteria Protein Functions
Negative Control   
pT18 + pT25 412.0 ± 82.4 pT18: Empty vector
Positive Control:   pT25: Empty vector
pT18-PknD + pT25-CdsD-FHA-2 996.3 ± 50.0 FliI: Putative flagellar ATPase
Negative Interactions:   FliF: Putative flagellar MS ring protein
pT18-FliI + pT25-FliF 396.4 ± 32.1 FlhA: Putative flagellar integral membrane
pT18-FliF + pT25-Cpn0859 421.1 ± 25.9 protein
pT18-FliI + pT25-Cpn0706 404.4 ± 19.5 Cpn0859: Hypothetical C. pneumoniae
pT18-Cpn0706 + pT25-FlhA 443.0 ± 32.3 protein
Positive Interactions:   Cpn0706: Putative T3S chaperone
pT18-FliF + pT25-FlhA 847.2 ± 21.2 CdsL: Putative T3S ATPase tethering
pT18-FliI + pT25-FlhA 942.9 ± 123.1 protein
pT18-FliI + pT25-CdsL 874.3 ± 59.3 CopN: Putative T3S plug protein
pT18-FliI + pT25-CopN 943.2 ± 74.2 Cpn0322: Putative CdsU ortholog
pT18-Cpn0322 + pT25-FlhA 779.9 ± 32.7  
pT18-CdsL + pT25-FlhA 832.1 ± 23.3  
  1. * FliI, FliF, FlhA, CdsL, CopN, Cpn0706 and Cpn0322 were cloned into both the pT18 and pT25 vectors. The bacterial-2-hybrid was performed in triplicate as described in the Materials and Methods section. Empty pT18 and pT25 vectors were used as a negative control while pT18-PknD + pT25-CdsD-FHA-2 was used as a positive control. The cut off for a positive interaction (577 units of activity/mg protein), is the mean of the negative control values (empty pT18 + pT25) plus two standard deviations obtained from 20 assays.