Lawsonia intracellularis contains a gene encoding a functional rickettsia-like ATP/ADP translocase for host exploitationJournal of Bacteriology (2008)
ATP/ADP translocases are a hallmark of obligate intracellular pathogens related to chlamydiae and rickettsiae.
These proteins catalyze the highly specific exchange of bacterial ADP against host ATP and thus allow
bacteria to exploit their hosts’ energy pool, a process also referred to as energy parasitism. The genome
sequence of the obligate intracellular pathogen Lawsonia intracellularis (Deltaproteobacteria), responsible for
one of the most economically important diseases in the swine industry worldwide, revealed the presence of a
putative ATP/ADP translocase most similar to known ATP/ADP translocases of chlamydiae and rickettsiae
(around 47% amino acid sequence identity). The gene coding for the putative ATP/ADP translocase of L.
intracellularis (L. intracellularis nucleotide transporter 1 [NTT1Li]) was cloned and expressed in the heterologous
host Escherichia coli. The transport properties of NTT1Li were determined by measuring the uptake of
radioactively labeled substrates by E. coli. NTT1Li transported ATP in a counterexchange mode with ADP in
a highly specific manner; the substrate affinities determined were 236.3 ( 36.5) M for ATP and 275.2 (
28.1) M for ADP, identifying this protein as a functional ATP/ADP translocase. NTT1Li is the first ATP/ADP
translocase from a bacterium not related to Chlamydiae or Rickettsiales, showing that energy parasitism by
ATP/ADP translocases is more widespread than previously recognized. The occurrence of an ATP/ADP translocase in L. intracellularis is explained by a relatively recent horizontal gene transfer event with rickettsiae as donors.
Publication DateSeptember, 2008
Citation InformationStephan Schmitz-Esser, Ilka Haferkamp, Silvia Knab, Thomas Penz, et al.. "Lawsonia intracellularis contains a gene encoding a functional rickettsia-like ATP/ADP translocase for host exploitation" Journal of Bacteriology Vol. 190 Iss. 17 (2008) p. 5746 - 5752
Available at: http://works.bepress.com/stephan-schmitz-esser/16/