Isolation and composition of sheathed flagella from Bdellovibrio bacteriovorus 109J

Abstract

A procedure was developed for the purification of sheathed flagella from Bdelovibrio bacteriovorus 109J. Preparations of isolated flagella appeared as filaments 28 nm in diameter, did not vary in sheath content by more than 10% from the mean, and contained 50% protein, 38% phospholipid, and 12% lipopolysaccharide (LPS) by weight. The sheath was readily solubilized by Triton X-100% whether or not EDTA was present, and contained all of the LPS and phospholipid and 30 to 40% of the protein of the intact flagella; sedimentable core filament polypeptides accounted for the remainder. Flagellar LPS was significantly enriched in nonadecenoic acid (19:1) and depleted in 0-hydroxymyristic acid relative to outer membrane LPS from intraperiplasmically grown bdellovibrios. These observations suggest that the sheath is a stable domain distinct from the bulk of the outer membrane. The sheath also contained substantially more phospholipid (57%) and less protein (26%) of a more heterogeneous composition than that of previously described outer membranes. This unusual balance of constituents was predicted to result in a fluid membrane compatible with a model for the generation of motility by rotation of the core filament within a highly flexible sheath.Bdellovibrio bacteriovorus is unique among the procaryotes in that growth and reproduction occur only within the intraperiplasmic space of other gram-negative species. Highly motile, free bdellovibrios collide violently with suitable substrate cells, attach, penetrate the outer envelope, and enter the periplasmic space. As the bdellovibrios grow on substrate cell components, they increase in length and diameter, forming a coiled cyclinder. Upon completion of growth, the cylinder fragments, and the bdelloplast wall is lysed which releases the motile progeny cells, which swim away completing the cycle. (For recent reviews, see references 36 and 45.) Motility is due to a single polar flagellum and is believed to be necessary for attachment. The flagellum is lost upon penetration into the substrate cell and is reformed by the progeny bdellovibrios before their release. Two features, a unique waveform and an unusually large diameter, distinguish bdellovibrio flagella from those of other bacterial species. The waveform, which decreases in wavelength and amplitude from the cell outward (D. Abram and M. Shilo, Bacteriol. Proc., p. 41, 1967) is in contrast to the constant periodicity exhibited by most other bacterial flagella. The exceptional thickness of the flagella is due to the presence of a flagellar sheath which encloses an inner core filament comparable in diameter and superficial appearance to unsheathed bacterial flagella (1,40,46). The sheath appears to be physically continuous with the cell outer membrane (4, 40, 45), but observations made by electron microscopy (1) suggest that the two domains may differ in composition.To examine the relationship between the sheath and the outer membrane, we isolated intact sheathed flagella. Here we present analytical data suggesting that the ...

The sheathed flagellum of Brucella melitensis is involved in persistence in a murine model of infection

“…and Helicobacter sp. (Thomashow and Rittenberg, 1985;Hernandez and Monge-Najera, 1994). This is the first description of synthesis of a sheathed flagellum in alphaproteobacteria.…”

“…and Bdellovibrio sp. (Thomashow and Rittenberg, 1985;Fuerst and Perry, 1988;Hernandez and Monge-Najera, 1994).…”

Flagella and Swimming Behavior of Marine Magnetotactic Bacteria

“…Sheath or pseudo-sheaths, each enclosing a single flagellum, have been reported for Caulobacter crescentus [28], Pseudomonas rhodos [29], Vibrio spp. [16], Helicobacter pylori [30], and Bdellovibrio bacteriovorus [31]. These flagellar sheath structures are believed to be an extension of the outer membrane.…”

Bacterial predation under changing viscosities

“…AP cells can be extremely fast, reaching velocities of up to 160 μms −1 (Lambert et al, 2006). In Bdellovibrio bacteriovorus (Oligoflexia), this is achieved by the action of a sheathed flagellum that can reach about 10 times the cell's size, has a damping waveform, (Thomashow and Rittenberg, 1985), and is composed of multiple flagellin proteins (Lambert et al, 2006). Viability rapidly dwindles as a result of high endogenous respiration rates and starvation (Hespell et al, 1974), which is possibly brought about by the energy requirements of such a high swimming speed (Mitchell, 1991).…”