Cloning and analysis of the first cry gene from Bacillus popilliae

• Published in: Journal of Bacteriology 1997-07, Vol.179 (13), p.4336-4341
• Main Authors: Zhang, J, Hodgman, T.C, Krieger, L, Schnetter, W, Schairer, H.U
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; AMINO ACID SEQUENCES; Animals; BACILLUS; Bacillus - genetics; Bacillus popilliae; Bacteria; Bacterial Proteins - analysis; Bacterial Proteins - genetics; BACTERIAL TOXINS; Bacterial Toxins - analysis; Bacterial Toxins - genetics; Bacteriology; Base Sequence; CHEMICAL COMPOSITION; CHROMOSOME; Chromosome Mapping; CHROMOSOMES; CLONACION; CLONAGE; CLONING; Cloning, Molecular; Coleoptera - microbiology; COMPOSICION QUIMICA; COMPOSITION CHIMIQUE; CROMOSOMAS; CRYBP1 GENE; CRYSTAL PROTEINS; DNA, Bacterial; Endotoxins - analysis; Endotoxins - genetics; GENBANK/X99049; GENE; GENE LOCATION; GENES; Genes, Bacterial; LOCALISATION DE GENE; LOCALIZACION DE GENES; Melolontha melolontha; MOLECULAR SEQUENCE DATA; MOLECULAR WEIGHT; NUCLEOTIDE SEQUENCE; OPEN READING FRAMES; OPERONS; PESO MOLECULAR; POIDS MOLECULAIRE; Polymerase Chain Reaction; Promoter Regions, Genetic; PROMOTERS; PROTEINAS; PROTEINE; PROTEINS; Scarabaeidae; SECUENCIA NUCLEOTIDICA; Sequence Analysis, DNA; Sequence Homology, Amino Acid; SEQUENCE NUCLEOTIDIQUE; STRUCTURAL GENES; TOXINAS BACTERIANAS; TOXINE BACTERIENNE
• ISSN: 0021-9193; 1098-5530; 1067-8832
• DOI: 10.1128/jb.179.13.4336-4341.1997

An 80-kDa parasporal crystal protein was detected in protein extracts of sporangia of Bacillus popilliae isolated from a diseased larva of the common cockchafer (Melolontha melolontha L.). Amino acid analysis of tryptic peptides revealed significant homology to the Cry2Aa endotoxins of Bacillus thuringiensis. The gene cryBP1 (cry18Aa1 ), which codes for the parasporal crystal protein, was found in a putative cry operon on the bacterial chromosome, which contains at least one further (smaller) open reading frame, orf1. The 706-amino-acid-long CryBP1 (Cry18Aa1) protein has a predicted molecular mass of 79 kDa and shows about 40% sequence identity to the Cry2 polypeptides of B. thuringiensis. In the light of published observations which suggest that the parasporal crystal proteins of B. popilliae are slightly toxic to their grub hosts, we propose the following survival strategy of B. popilliae. As an obligate pathogen of grubs, B. popilliae germinates in the gut of a grub and the parasporal crystal proteins are released and activated. The activated protein does not cause colloid osmotic lysis but instead damages the gut wall somehow to allow the vegetative cells to enter the hemolymph more easily. By becoming a parasite, B. popilliae can continue to proliferate efficiently while the living grub provides a food supply. This process is in contrast to that of B. thuringiensis, which rapidly kills the insect and is then limited to growth on the larval carcass