The bacteriophage kh receptor of Lactococcus lactis subsp. cremoris KH is the rhamnose of the extracellular wall polysaccharide

Abstract

A receptor for bacteriophages of lactic acid bacteria, including Lactococcus lactis subsp. cremoris KH, was found on the cell wall and not on the cell membrane, as determined by a phage-binding assay of sodium dodecyl sulfate-and mutanolysin-treated cell walls. The cell wall carbohydrates of L. lactis subsp. cremoris KH were analyzed by gas chromatography and mass spectrometry and found to contain rhamnose, galactose, glucose and N-acetylglucosamine. Similar analysis of mutants that were reduced in the ability to bind phages kh, 643, c2, m13, and 1 indicated that galactose was essential for binding all phages. In addition, rhamnose was required for binding phages kh and m13. Inhibition studies of phage binding by using two different lectins with a specificity for galactose indicated that phage kh may not bind directly to galactose. Rather, galactose may be an essential structural component located in the vicinity of the receptor. Incubation of any of the five phages with rhamnose or of phage kh with purified cell walls inactivated the phages. Inactivation required divalent cations and was irreversible. Inactivation of phages was stereospecific for rhamnose, as neither L-(+)-nor D-(-)-fucose (the stereoisomers of rhamnose) inhibited the phage. Furthermore, phage infection of a culture was completely inhibited by the addition of rhamnose to the medium. Therefore, the receptor for phage kh appears to be a rhamnose component of the extracellular wall polysaccharide. * Corresponding author. t Oregon State University Agricultural Experiment Station communication no. 9022.

Temperate phages TP901-1 and ϕLC3, belonging to the P335 species, apparently use different pathways for DNA injection inLactococcus lactissubsp.cremoris3107

“…In a number of lactococcal phage/host systems, phage adsorption has been shown to involve attachment of the phage to a carbohydrate moiety in the cell wall, such as galactose and/or rhamnose and to a lesser extent glucose (Keogh & Pettingill, 1983;Valyasevi et al, 1990Valyasevi et al, , 1995Monteville et al, 1994). For phage c2, the primary adsorption step was found to be reversible, whereas the following binding to a receptor in the cell membrane was found to be irreversible (Valyasevi et al, 1991;Monteville et al, 1994).…”

Bacteriophage receptors of Lactococcus lactis subsp. ?diacetylactis? F7/2 and Lactococcus lactis subsp. cremoris Wg2-1

“…However, Sijtsma et al [7] showed that ConA reduced phage binding ability of L. lactis subsp, cremoris SKl12 essentially. Similarly, phage adsorption efficiency of L lactis subsp, cremoris KH [4] was considerably affected by the presence of the lectin from Momordica charantia (specific for n-galactose). These different responses of lactococcal cells and cell walls reflect strain specific differences in carbohydrate components participating in phage receptor structures.…”

“…They found phage binding to cell walls and, in one case, to the cytoplasmatic membrane of N-streptococci [3]. Recently, Valyasevi et al [4] reported that adsorption of five phages to L. lactis subsp. cremoris KH was significantly inhibited by Lrhamnose.…”

A protein which masks galactose receptor mediated phage susceptibility in Lactococcus lactis subsp. lactis MPL56

“…Cell walls were prepared according to the method of Valyasevi et al (1990). Cell walls (0.1 mg) were mixed with 0.1, 0.05 and 0.025 mg lectins from concanavalin A (Con A), Vicia sativa, Momordica charantia and Bandeiraea simplificifolia (Sigma Chemical Co., St Louis, MO, USA) in a final volume of 1.0 mL of 50 mM Tris-HCl, pH 6.8, and incubated for 20 min at 25°C.…”