Article Abstract:
The potential interactions of the transcriptional regulator AmpR with intermediates of the degradative and/or biosynthetic pathways of murein metabolism in gram negative bacteria were investigated. Transcription assay results revealed that AmpR activates ampC beta-lactamase synthesis. The murein precursor, UDP-MurNAc-pentapeptide, on the other hand, inhibits AmpR-mediated transcriptional activation in vitro but such inhibition can be offset by the action of the muropeptide, anhMurNAc-tripeptide which accumulates in beta-lactamase-overproducing mutants. It is thus evident that cytosolic intermediates of murein biosynthesis and degradation operate as a cell-wall sensing device as they control beta-lactamase production.
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Article Abstract:
The only family of bacterial proteins identified to have an immunoglobulin fold is needed for the assembly of adhesive pili. These proteins employ their unique immunoglobulin features in recognition processes that are being studied. Investigations into the action of periplasmic chaperones also reveal a great deal about the basic biological processes of assembly functions. Not all bacterial adhesins are assembled into pilus rods, and the ones that cannot are called nonpilus adhesins.
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Article Abstract:
Injection of effector proteins into host cells by gram-positive bacterium Streptococcus pyogenes is mediated by a cholesterol-dependent cytolysin, streptolysin O. Data indicate that the effector molecule, S. pyogenes NAD-glycohydrolase, is transported through a pore in streptolysin O.
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