Dynamics in oxygen-induced changes in S-layer protein synthesis from Bacillus stearothermophilus PV72 and the S-layer-deficient variant T5 in continuous culture and studies of the cell wall composition.
Stable synthesis of the hexagonally ordered (p6) S-layer protein from the wild-type strain of Bacillus stearothermophilus PV72 could be achieved in continuous culture on complex medium only under oxygen-limited conditions when glucose was used as the sole carbon source. Depending on the adaptation of the wild-type strain to low oxygen supply, the dynamics in oxygen-induced changes in S-layer protein synthesis was different when the rate of aeration was increased to a level that allowed dissimilation of amino acids. If oxygen supply was increased at the beginning of continuous culture, synthesis of the p6 S-layer protein from the wild-type strain (encoded by the sbsA gene) was immediately stopped and replaced by that of a new type of S-layer protein (encoded by the sbsB gene) which assembled into an oblique (p2) lattice. In cells adapted to a prolonged low oxygen supply, first, low-level p2 S-layer protein synthesis and second, synchronous synthesis of comparable amounts of both types of S-layer proteins could be induced by stepwise increasing the rate of aeration. The time course of changes in S-layer protein synthesis was followed up by immunogold labelling of whole cells. Synthesis of the p2 S-layer protein could also be induced in the p6-deficient variant T5. Hybridization data obtained by applying the radiolabelled N-terminal and C-terminal sbsA fragments and the N-terminal sbsB fragment to the genomic DNA of all the three organisms indicated that changes in S-layer protein synthesis were accompanied by chromosomal rearrangement. Chemical analysis of peptidoglycan-containing sacculi and extraction and recrystallization experiments revealed that at least for the wild-type strain, a cell wall polymer consisting of N-acetylglucosamine and glucose is responsible for binding of the p6 S-layer protein to the rigid cell wall layer.
Sára
M
M
Zentrum für Ultrastrukturforschung, Universität für Bodenkultur, Vienna, Austria.
Kuen
B
B
Mayer
H F
HF
Mandl
F
F
Schuster
K C
KC
Sleytr
U B
UB
D000222:Adaptation, Physiological; D000595:Amino Acid Sequence; D000907:Antibodies, Bacterial / Q000276:immunology; D000918:Antibody Specificity; D001425:Bacterial Outer Membrane Proteins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D001426:Bacterial Proteins; D015139:Blotting, Southern; D002473:Cell Wall / Q000737:chemistry*; D003460:Crystallization; D017353:Gene Deletion; D014644:Genetic Variation; D001411:Geobacillus stearothermophilus / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D015151:Immunoblotting; D008562:Membrane Glycoproteins; D008969:Molecular Sequence Data; D010100:Oxygen / Q000378:metabolism*; D010457:Peptidoglycan / Q000737:chemistry
D000907:Antibodies, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D008562:Membrane Glycoproteins; D010457:Peptidoglycan; C055764:S-layer proteins; D010100:Oxygen