A general strategy for identification of S-layer genes in the Bacillus cereus group: molecular characterization of such a gene in Bacillus thuringiensis subsp. galleriae NRRL 4045.
Despite its possible role in virulence, there has been little molecular characterization of members of the S-layer protein family of the Bacillus cereus group. It is hypothesized that the components of the S-layers are likely to display similar anchoring structures in Bacillus thuringiensis and Bacillus anthracis. Based on inferred sequence similarities, a DNA fragment encoding the cell-wall-anchoring domain of an S-layer component of BAC: thuringiensis subsp. galleriae NRRL 4045 was isolated. The complete gene was identified and sequenced. An ORF of 2463 nt was identified, which was predicted to encode a protein of 821 aa, SlpA. The mature SlpA protein (792 residues) carries three S-layer homology (SLH) motifs towards its amino terminus, each about 50 aa long. These motifs were sufficient to bind Bac. thuringiensis and Bac. anthracis cell walls in vitro by interacting with peptidoglycan-associated polymers, confirming a common wall-anchoring mechanism. The slpA null-allele mutant was constructed and shown to possess no other abundant surface protein. It is proposed that the method described in this paper could be applied to the identification and deletion of any Bac. cereus S-layer gene and is of great value for the molecular and functional characterization of these genes.
Mesnage
Stéphane
S
Toxines et Pathogénie Bactériennes (URA 2172, CNRS), Institut Pasteur, 28 rue du Dr Roux, 75724, Paris cédex 15, France1.
Haustant
Michel
M
Toxines et Pathogénie Bactériennes (URA 2172, CNRS), Institut Pasteur, 28 rue du Dr Roux, 75724, Paris cédex 15, France1.
Fouet
Agnès
A
Toxines et Pathogénie Bactériennes (URA 2172, CNRS), Institut Pasteur, 28 rue du Dr Roux, 75724, Paris cédex 15, France1.
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001409:Bacillus cereus / Q000235:genetics* / Q000378:metabolism; D001413:Bacillus thuringiensis / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D002473:Cell Wall / Q000378:metabolism; D005798:Genes, Bacterial / Q000235:genetics*; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D010457:Peptidoglycan / Q000378:metabolism; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
D001426:Bacterial Proteins; D010457:Peptidoglycan; C070683:surface layer protein A, Bacteria