Reattachment of surface array proteins to Campylobacter fetus cells

Abstract

Campylobacterfetus strains may be of serotype A or B, a property associated with lipopolysaccharide (LPS) structure. Wild-type C. fetus strains contain surface array proteins (S-layer proteins) that may be extracted in water and that are critical for virulence. To explore the relationship of S-layer proteins to other surface components, we reattached S-layer proteins onto S-template cells generated by spontaneous mutation or by serial extractions of S' cells with water. Crystalline surface layers have been observed as the outermost component of the bacterial cell envelopes in numerous gram-positive and gram-negative species (38) and are composed of protein subunits assembled over the cell surface into two-dimensional arrays with hexagonal (p6), square (p4), or oblique (p2) symmetry (36). For the majority of bacteria, the surface layer is formed from a single species of protein, known as a surface array protein (S-layer protein), which is acidic and generally hydrophobic (36,38). In gram-negative bacteria, the constituent subunits of most S-layers interact with each other and with the underlying outer membrane components (3,35,37,40), such as outer membrane proteins in an Acinetobacter sp. (41), lipid-lipopolysaccharide (LPS) in Spirillum serpens (11), and LPS in Aeromonas salmonicida (2, 22), and many S-layers require divalent cations for assembly (10,37,40).

Nested DNA inversion of Campylobacter fetus S-layer genes is recA dependent

“…To facilitate expression, the Campylobacter coli tetO cassette (33) was positioned downstream of the highly active sapA promoter, which normally permits the expression of approximately 10 5 copies of SLPs per cell per generation (64). Attempts to express the tetracycline resistance gene in C. jejuni by using tetO with its native promoter were unsuccessful (19a).…”

Identification of lipopolysaccharide O antigen synthesis genes required for attachment of the S-layer of Caulobacter crescentus The GenBank accession number for the NA1000 rsaADEF and gmd, per, wbqA, wbqR, wbqX and wbqZ sequences reported in this paper is AF06235.

“…The lipid A moiety is anchored in the outer leaflet of the outer membrane. The core, a branched chain oligo-Although there is only a limited number of instances identified so far, it appears that in Gram-negative bacteria S-LPS is required for attachment of the S-layer (Boot & Pouwels, 1996 ;Yang et al, 1992). This is the case in C. crescentus where the S-LPS anchors the Slayer to the cell surface (Walker et al, 1994).…”

The S‐layer protein of Corynebacterium glutamicum is anchored to the cell wall by its C‐terminal hydrophobic domain

“…It is also found in cell-wall proteins presumed to be anchored to peptidoglycan. Yang et al (1992) proposed that S-layer proteins of Campylobacter fetus interact via their N-terminal domain with lipopolysaccharide. Similar results were obtained by Walker et al (1994), who proposed that the S-layer proteins of Caulobacter crescentus interact with lipopolysaccharide via calcium bridges.…”