scholarly journals Surface Expression of the Conserved C Repeat Region of Streptococcal M6 Protein within the Pip Bacteriophage Receptor ofLactococcus lactis

2001 ◽  
Vol 67 (12) ◽  
pp. 5370-5376 ◽  
Author(s):  
Bruce L. Geller ◽  
Nadine Wade ◽  
Thomas D. Gilberts ◽  
Dennis E. Hruby ◽  
Ryan Johanson ◽  
...  
Keyword(s):  
Cell Surface ◽  
Copy Number ◽  
Culture Medium ◽  
Surface Expression ◽  
High Copy Number ◽  
Repeat Region ◽  
Western Blots ◽  
Proteolytic Fragment ◽  
Copy Number Plasmid ◽  
High Copy Number Plasmid

ABSTRACT The C repeat region of the M6 protein (M6c) fromStreptococcus pyogenes was expressed within the Pip bacteriophage receptor on the surface of Lactococcus lactis. M6c was also detected in the culture medium. Thepip-emm6c allele was integrated into the chromosome and stably expressed without antibiotic selection. The level of cell-associated surface expression of PipM6c was 0.015% of total cellular protein. The amount of PipM6c on the cell surface was increased about 17-fold by expressing pip-emm6c from a high-copy-number plasmid. Replacing the native pippromoter with stronger promoters isolated previously fromLactobacillus acidophilus increased surface expression of PipM6c from the high-copy-number plasmid up to 27-fold. Concomitantly, the amount of PipM6c in the medium increased 113-fold. The amount of PipM6c did not vary greatly between exponential- and stationary-phase cultures. Western blots indicated that the full-length PipM6c protein and most of the numerous proteolytic products were found only on the cell surface, whereas only one proteolytic fragment was found in the culture medium.

scholarly journals Nucleotide sequence of a high copy number plasmid fromHalobacteriumstrain GRB

1990 ◽  
Vol 18 (11) ◽  
pp. 3408-3408 ◽  
Author(s):  
Neil R. Hackett ◽  
Mark P. Krebs ◽  
Shiladitya DasSarma ◽  
Werner Goebel ◽  
Uttam L. RajBhandary ◽  
...  
Keyword(s):  
Nucleotide Sequence ◽  
Copy Number ◽  
High Copy Number ◽  
Copy Number Plasmid ◽  
High Copy Number Plasmid

Development of Small High-Copy-Number Plasmid Vectors for Gene Expression in Caulobacter crescentus

Plasmid ◽  
2001 ◽  
Vol 46 (1) ◽  
pp. 37-46 ◽  
Author(s):  
Elizabeth Umelo-Njaka ◽  
John F. Nomellini ◽  
Harry Yim ◽  
John Smit
Keyword(s):  
Gene Expression ◽  
Copy Number ◽  
Caulobacter Crescentus ◽  
High Copy Number ◽  
Plasmid Vectors ◽  
Copy Number Plasmid ◽  
High Copy Number Plasmid

scholarly journals Phosphoethanolamine substitution in the lipid A of Escherichia coli O157 : H7 and its association with PmrC

Microbiology ◽  
2006 ◽  
Vol 152 (3) ◽  
pp. 657-666 ◽  
Author(s):  
Sang-Hyun Kim ◽  
Wenyi Jia ◽  
Valeria R. Parreira ◽  
Russell E. Bishop ◽  
Carlton L. Gyles
Keyword(s):  
Escherichia Coli ◽  
Copy Number ◽  
Lipid A ◽  
High Copy Number ◽  
Peptide Antibiotics ◽  
Significant Similarity ◽  
E Coli ◽  
Copy Number Plasmid ◽  
High Copy Number Plasmid ◽  
K 12

This study shows that lipid A of Escherichia coli O157 : H7 differs from that of E. coli K-12 in that it has a phosphoform at the C-1 position, which is distinctively modified by a phosphoethanolamine (PEtN) moiety, in addition to the diphosphoryl form. The pmrC gene responsible for the addition of PEtN to the lipid A of E. coli O157 : H7 was inactivated and the changes in lipid A profiles were assessed. The pmrC null mutant still produced PEtN-modified lipid A species, albeit in a reduced amount, indicating that PmrC was not the only enzyme that could be used to add PEtN to lipid A. Natural PEtN substitution was shown to be present in the lipid A of other serotypes of enterohaemorrhagic E. coli and absent from the lipid A of E. coli K-12. However, the cloned pmrC O157 gene in a high-copy-number plasmid generated a large amount of PEtN-substituted lipid A species in E. coli K-12. The occurrence of PEtN-substituted lipid A species was associated with a slight increase in the MICs of cationic peptide antibiotics, suggesting that the lipid A modification with PEtN would be beneficial for survival of E. coli O157 : H7 in certain environmental niches. However, PEtN substitution in the lipid A profiles was not detected when putative inner-membrane proteins (YhbX/YbiP/YijP/Ecf3) that show significant similarity with PmrC in amino acid sequence were expressed from high-copy-number plasmids in E. coli K-12. This suggests that these potential homologues are not responsible for the addition of PEtN to lipid A in the pmrC mutant of E. coli O157 : H7. When cells were treated with EDTA, the amount of palmitoylated lipid A from the cells carrying a high-copy-number plasmid clone of pmrC O157 that resulted in significant increase of PEtN substitution was unchanged compared with cells without PEtN substitution, suggesting that the PEtN moiety substituted in lipid A does not compensate for the loss of divalent cations required for bridging neighbouring lipid A molecules.

Overproduction of Gene Products by the Super-High-Copy-Number Plasmid pNR333

1987 ◽  
Vol 31 (8) ◽  
pp. 737-744
Author(s):  
Akihiko Mochizuki ◽  
Sankichi Horiuchi ◽  
Nobuichi Goto ◽  
Rintaro Nakaya
Keyword(s):  
Copy Number ◽  
High Copy Number ◽  
Gene Products ◽  
Copy Number Plasmid ◽  
High Copy Number Plasmid
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