Comparison of Plasmids ColE2-P9 and ColE2-CA42 and Their Immunity Proteins

Watson, Robert J.; Konarska-Kozlowska, M.; Iyer, Narayan V.; Yaguchi, Makoto; Visentin, Louis P.

doi:10.1128/jb.153.3.1552-1557.1983

Cited by 9 publications

(1 citation statement)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…An open reading frame starting at nucleotide number 320 specified 86 amino acids and the sequence of the first 20 amino acids coincided with the N-terminal sequence of the ColE2-P9 immunity protein determined experimentally (10). A comparison of the amino acid composition deduced from this reading frame with those determined previously (10,35; Table 1) confirmed the immE2 gene to be located from 320 to 577.…”

Section: Clp Pmt221supporting

confidence: 75%

Structure and expression of the ColE2-P9 immunity gene

1985

View full text Add to dashboard Cite

The primary structure and expression of the ColE2-P9 immunity gene (imm) were investigated. The imm gene is located behind the colicin gene (col) in the same orientation with an intergenic space of two base pairs. Although the imm gene was transcribed primarily in response to the SOS function of the host cell as well as the col gene, the immunity phenotype also appeared to be expressed by only a slight level of leaky transcription without an evident promoter. On comparing the ColE2-P9 sequence with those of relevant plasmids, a highly homologous sequence with the immE2 gene was found downstream of the immE3 gene of ColE3-CA38, and thus, an evolutional relationships could be deduced among some E-group Col plasmids.

show abstract

Section: Clp Pmt221supporting

confidence: 75%

Structure and expression of the ColE2-P9 immunity gene

1985

View full text Add to dashboard Cite

show abstract

Molecular characterisation of the colicin E2 operon and identification of its products

1985

View full text Add to dashboard Cite

The DNA sequence of the entire colicin E2 operon was determined. The operon comprises the colicin activity gene, ceaB, the colicin immunity gene, ceiB, and the lysis gene, celB, which is essential for colicin release from producing cells. A potential LexA binding site is located immediately upstream from ceaB, and a rho-independent terminator structure is located immediately downstream from celB. A comparison of the predicted amino acid sequences of colicin E2 and cloacin DF13 revealed extensive stretches of homology. These colicins have different modes of action and recognise different cell surface receptors; the two major regions of heterology at the carboxy terminus, and in the carboxy-terminal end of the central region probably correspond to the catalytic and receptor-recognition domains, respectively. Sequence homologies between colicins E2, A and E1 were less striking, and the colicin E2 immunity protein was not found to share extensive homology with the colicin E3 or cloacin DF13 immunity proteins. The lysis proteins of the ColE2, ColE1 and CloDF13 plasmids are almost identical except in the aminoterminal regions, which themselves have overall similarity with lipoprotein signal peptides. Processing of the ColE2 prolysis protein to the mature form was prevented by globomycin, a specific inhibitor of the lipoprotein signal peptidase. The mature ColE2 lysis protein was located in the cell envelope. The results are discussed in terms of the functional organisation of the colicin operons and the colicin proteins, and the way in which colicins are released from producing cells.

show abstract

Replication of ColE2 and ColE3 plasmids: The regions sufficient for autonomous replication

Horii

Itoh

1988

Mol Gen Genet

View full text Add to dashboard Cite

We have localized the regions sufficient for autonomous replication on the genomes of the colicin E2 (ColE2) and colicin E3 (ColE3) plasmids and analyzed the replication functions carried by these regions. A 1.3 kb segment of each plasmid is sufficient for autonomous replication. Plasmids carrying this segment retain the replication properties of the original plasmid. The 1.3 kb segment consists of three functional portions. Firstly, a 0.9 kb region which specifies at least one trans-acting factor required for replication of each plasmid. Secondly, a 0.4 kb region located adjacent to one end of the 0.9 kb region, which is required for expression of the trans-acting factor(s) and probably contains the promoter. The region across the border of these two portions of ColE2 is involved in copy number control of the plasmid. The third portion is a 50 bp region adjacent to the other end of the 0.9 kb region, which contains a cis-acting site (origin) where replication initiates in the presence of the trans-acting factor(s). The action of the trans-acting factor(s) on the origin is plasmid specific. The 50 bp regions functioning as the origins of replication of ColE2 and ColE3 are the smallest among those in prokaryotic replicons so far identified and analyzed.

show abstract

Comparison of Plasmids ColE2-P9 and ColE2-CA42 and Their Immunity Proteins

Cited by 9 publications

References 11 publications

Structure and expression of the ColE2-P9 immunity gene

Structure and expression of the ColE2-P9 immunity gene

Molecular characterisation of the colicin E2 operon and identification of its products

Replication of ColE2 and ColE3 plasmids: The regions sufficient for autonomous replication

Contact Info

Product

Resources

About