Degradation of Escherichia coli beta-galactosidase fragments in protease-deficient mutants of Salmonella typhimurium.
AUTOR(ES)
Miller, C G
RESUMO
The degradation rates of several mutationally generated fragments of Escherichia coli beta-galactosidase were determined in wild-type strains of Salmonella typhimurium and in mutant Salmonella strains lacking several proteases and peptidases. Three termination fragments (produced by lacZ545, lacZ521, and lacZX90) and one internal reinitiation (restart) fragment [lacZpi(1)] are degraded in wild-type Salmonella strains at the same rates observed in wild-type Escherichia coli strains. Mutations that lead to loss of peptidases N, A, B, P, and Q or to loss of protease I or II do not affect the decay rates of any of these fragments. In addition, all of these peptidases and proteases are present in E coli mutants carrying deg mutations (deg mutations are known to stabilize beta-galactosidase fragments). Apparently, none of the proteases and peptidases that are currently accessible to direct genetic analysis plays a role in the early steps of the degradation of protein fragments.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=235212Documentos Relacionados
- Efflux of beta-galactosidase products from Escherichia coli.
- Oral Immunization with ATP-Dependent Protease-Deficient Mutants Protects Mice against Subsequent Oral Challenge with Virulent Salmonella enterica Serovar Typhimurium
- The amino acid sequence of beta-galactosidase of Escherichia coli.
- Kinectics of beta-galactosidase synthesis in Escherichia coli at 5 C.
- Genetic regulation: yeast mutants constitutive for beta-galactosidase activity have an increased level of beta-galactosidase messenger ribonucleic acid.