Repressor and Antirepressor in the Regulation of Staphylococcal Penicillinase Synthesis
AUTOR(ES)
Imsande, John
RESUMO
5-methyltryptophan (5MT) induces penicillinase synthesis in Staphylococcus aureus. The analog is incorporated into protein by both wild-type and tryptophan-starved cells. Since normal penicillinase repressor appears to contain tryptophan even though penicillinase itself does not, it is concluded that 5MT induces penicillinase synthesis by becoming incorporated into the penicillinase repressor and thereby inactivating the repressor. Thus biochemical data support the existence of a penicillinase repressor and indicate that penicillinase synthesis is regulated by negative control and not by positive control.—In the absence of exogenous tryptophan, staphylococcal penicillinase induction can be inhibited by 7-azatryptophan (7azaT). Because 7azaT is incorporated into protein by tryptophan-starved cells, it is concluded that 7azaT blocks penicillinase induction by inactivating a penicillinase regulatory protein into which the analog has been incorporated. Incorporation of 7azaT does not appear to inactivate the operator binding site or the effector binding site on the penicillinase repressor. Therefore, it appears that 7azaT blocks penicillinase induction by inactivating the penicillinase antirepressor, a protein required for inactivation of the penicillinase repressor and, hence, required for penicillinase induction.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1212988Documentos Relacionados
- Regulation of Staphylococcal Penicillinase Synthesis
- Cloning and nucleotide sequence of the penicillinase antirepressor gene penJ of Bacillus licheniformis.
- Regulation of Penicillinase Synthesis: a Mutation in Staphylococcus aureus Unlinked to the Penicillinase Plasmid That Reduces Penicillinase Inducibility
- Nucleotide Sequence of the Penicillinase Repressor Gene penI of Bacillus licheniformis and Regulation of penP and penI by the Repressor
- Nucleotide sequence of the penicillinase repressor gene penI of Bacillus licheniformis and regulation of penP and penI by the repressor.
