The expression of the dodecameric ferritin in Listeria spp. is induced by iron limitation and stationary growth phase.

摘要: Abstract The Gram-positive bacterium Listeria innocua possesses an authentic ferritin with unusual dodecameric assemblage that resembles the quaternary structure of DNA-binding proteins designated Dps ( D NA-binding p roteins from s tarved cells). L. gene encoding above protein, termed fri ), has been localized on a 3-kb Hin dIII chromosomal fragment cloned in Escherichia coli strain DH5αF′. DNA sequence analysis reveals open reading frame 468 nucleotides matching perfectly amino acid protein. Primer extension indicates presence two transcriptional startpoints located 36 (proximal) and 85 nt (distal) upstream start codon, respectively. Each startpoint is preceded by suitably −10 −35 elements, which match σ A B consensus sequences. In Liseria monocytogenes , expression increases both upon entry into stationary phase and, more markedly, under low-iron growth conditions. effect iron apparent exponential phases growth. An up-regulation limitation never observed other proven ferritins bacterioferritins, but reported for several members family. regulation provides further support to evolutionary link family suggests storage function may not be unique role physiology this bacterium.