Transmembrane Cation Movements during Infection of Lactobacillus lactis by Bacteriophage LL-H

Abstract

SUMMARYPhage LL-H-induced cation (K +, Na +, Mg 2÷, Ca z÷, Cd 2+) movements in Lactobacillus lactis bacteria have been studied. The effects of the m.o.i, and external cation concentration have been quantified. LL-H-induced effluxes showed cation specificity: K+ but practically no Mg 2÷ was lost during LL-H infection at low and moderate m.o.i. (up to about 100). Simultaneously to K + efflux, divalent cation influxes were observed. These were dependent on the m.o.i, and on concentrations of external divalent cations and were concomitant with phage DNA transport, as concluded from the timing of the first phage-promoted biochemical changes in host cell metabolism and from electron microscopical observations. Host energy was not mobilized with phage-induced divalent cation influx. Several features of divalent cation influxes support the view that divalent cations have to be cotransported into the cell as counterions of LL-H DNA. Phage DNA associated with divalent cations may be the basic feature of the divalent cation dependence of LL-H infection.

Genetic Response to Bacteriophage Infection in Lactococcus lactis Reveals a Four-Strand Approach Involving Induction of Membrane Stress Proteins, d -Alanylation of the Cell Wall, Maintenance of Proton Motive Force, and Energy Conservation

“…These events occur at high rates (50 to 75%) even in highly efficient systems such as the coliphages T4 and T5 (1,20) and could therefore affect the infection of phage c2 (42,64). High MOIs (Ͼ100) can be associated with lysis of the cell population (68), but in both E. coli and Lactobacillus lactis, the most common effect appears to be inhibition of host lysis and extension of the latent period (2,68). In addition, T4-and T2-infected E. coli cells are known to be resistant to passive lysis due to high MOIs and are also able to exclude superinfecting phages (3,12).…”

Characterization of the LlaCI methyltransferase from Lactococcus lactis subsp. cremoris W15 provides new insights into the biology of type II restriction–modification systems

“…The survey performed by Hanish & McClelland (1988) was limited to only a few enzymes. The intracellular concentration of free Mg 2+ in E. coli cells was estimated to be in the range of 1-4 mM (Lusk et al, 1968;Alatossava et al, 1985) and it is very likely that this value is similar for other bacterial species, as common mechanisms are responsible for the accumulation of Mg 2+ inside bacterial cells (Moncrief & Maguire, 1999). These mechanisms appear to be omnipresent in prokaryotes (Kehres et al, 1998).…”

Physicochemical Properties of Cells and Their Effects on Intrinsically Disordered Proteins (IDPs)

“…Similarly, large variations in the total concentration of Mg 2+ have been reported, with estimates ranging from 20 35 to 100 mM, 36 although the amount of free Mg 2+ is estimated to be much smaller in comparison at 1–2 mM. 37,38 Estimates for other common inorganic ions include Na + at ∼5 mM, 34 Ca 2+ at ∼0.1 mM, 35 and CyberCell reports concentrations of Cl – and total phosphate (H 2 PO 4 – /HPO 4 2– /PO 4 3– ) at 6 and 5 mM, 30 respectively. Although variations between tissues exist, average concentrations of inorganic ions in E. coli , yeast and mammalian cells are in the same range.…”