Colicin A Immunity Protein Interacts with the Hydrophobic Helical Hairpin of the Colicin A Channel Domain in the
            <i>Escherichia coli</i>
            Inner Membrane

Nardi, Angèle; Corda, Yves; Baty, Daniel; Duché, Denis

doi:10.1128/jb.183.22.6721-6725.2001

Cited by 9 publications

(5 citation statements)

References 20 publications

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“…Using a coimmunoprecipitation procedure, Espesset et al showed that there is an interaction between the colicin A pore-forming domain bound to the cytoplasmic membrane and its immunity protein (189). This interaction did not require the channel to be in the open state but required the presence of the hydrophobic helical hairpin in the membrane (189,477), indicating that A-type immunity proteins can bind colicins prior to pore formation. In the E1-type colicin, the situation seems to be more complex, since the transmembrane helices recognized by the immunity protein are located in the voltage-gated region of the colicin.…”

Section: Pore-forming Colicinsmentioning

confidence: 99%

Colicin Biology

Cascales

Buchanan

Duché

et al. 2007

Microbiol Mol Biol Rev

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985

1,324

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SUMMARY Colicins are proteins produced by and toxic for some strains of Escherichia coli. They are produced by strains of E. coli carrying a colicinogenic plasmid that bears the genetic determinants for colicin synthesis, immunity, and release. Insights gained into each fundamental aspect of their biology are presented: their synthesis, which is under SOS regulation; their release into the extracellular medium, which involves the colicin lysis protein; and their uptake mechanisms and modes of action. Colicins are organized into three domains, each one involved in a different step of the process of killing sensitive bacteria. The structures of some colicins are known at the atomic level and are discussed. Colicins exert their lethal action by first binding to specific receptors, which are outer membrane proteins used for the entry of specific nutrients. They are then translocated through the outer membrane and transit through the periplasm by either the Tol or the TonB system. The components of each system are known, and their implication in the functioning of the system is described. Colicins then reach their lethal target and act either by forming a voltage-dependent channel into the inner membrane or by using their endonuclease activity on DNA, rRNA, or tRNA. The mechanisms of inhibition by specific and cognate immunity proteins are presented. Finally, the use of colicins as laboratory or biotechnological tools and their mode of evolution are discussed.

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Section: Pore-forming Colicinsmentioning

confidence: 99%

Colicin Biology

Cascales

Buchanan

Duché

et al. 2007

Microbiol Mol Biol Rev

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985

1,324

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“…Asterisks indicate conserved amino acids within the colicin proteins. Underlined amino acid sequence represent the 10 known alpha-helices as determined for ColA (27). Helices 8 and 9 are shown in grey.…”

Section: Vol 47 2003mentioning

confidence: 99%

“…Helices 8 and 9 are shown in grey. colicin molecule to a specific outer membrane receptor protein, the N-terminal domain mediates translocation through the cell envelope, and the C-terminal domain exerts the lethal effect (27,30).…”

Section: Vol 47 2003mentioning

confidence: 99%

Integration of a Transposon Tn 1 -Encoded Inhibitor-Resistant β-Lactamase Gene, bla _TEM-67 from Proteus mirabilis , into the Escherichia coli Chromosome

Naas

Zerbib

Girlich

et al. 2003

Antimicrob Agents Chemother

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Proteus mirabilis NEL-1 was isolated from a urine sample of a patient hospitalized in a long-term care facility. Strain NEL-1 produced a ␤-lactamase with a pI of 5.2 conferring resistance to amoxicillin and amoxicillin-clavulanic acid. Sequencing of a PCR amplicon by using TEM-specific primers revealed a novel bla TEM gene, bla TEM-67 . TEM-67 was an IRT-1-like TEM derivative related to TEM-65 (Lys39, Cys244) with an additional Leu21Ile amino acid substitution in the leader peptide. The biochemical properties of TEM-67 were equivalent to those described for TEM-65. Analysis of sequences surrounding bla TEM-67 revealed that it was located on a transposon, Tn1, which itself was located on a 48-kb non-self-transferable plasmid, pANG-1. Electroporation of plasmid pANG-1 into Escherichia coli DH10B resulted in the integration of bla TEM-67 into the chromosome, whereas it remained episomal in the P. mirabilis CIP103181 reference strain. Further characterization of pANG-1 revealed the presence of two identical sequences on both sides of Tn1 that contained an IS26 insertion sequence followed by a novel colicin gene, colZ, which had 20% amino acid identity with other colicin genes. The characterization of this novel TEM derivative provides further evidence for the large diversity of plasmid-encoded ␤-lactamases produced in P. mirabilis and for their spread to other enterobacterial species through transposable-element-mediated events.␤-Lactamase inhibitors, such as clavulanic acid, sulbactam, or tazobactam, are largely prescribed in association with amino-and ureidopenicillins for treating gram-negative infections (42). They are suicide inactivators of Ambler class A ␤-lactamases (1, 42). Several mechanisms, however, allow Enterobacteriaceae to overcome the efficacy of these molecules, such as overproduction of a cephalosporinase or of narrow-spectrum class A enzymes, limited uptake of the antibiotics, production of OXA-type enzymes, and production of ␤-lactamase inhibitor-resistant TEM or SHV derivatives (42).Since 1992, when the first inhibitor-resistant TEM (IRT) ␤-lactamase was identified, numerous IRT variants in Escherichia coli clinical isolates have been characterized, indicating a diversity of these ␤-lactamase genes (16). DNA sequence analyses have shown that the IRT enzymes differ from the TEM-1 progenitor by as many as three amino acid substitutions located predominantly at Ambler positions Met69, Trp165, Arg244, Arg275, and/or Asn276 (4, 16, 41). The first report of IRTs in Enterobacteriacae other than E. coli was that of Lemozy et al., who identified an IRT enzyme in Klebsiella pneumoniae (17). IRT ␤-lactamase-producing strains of K. pneumoniae may become epidemic (11). Bret et al. (3) described an IRT ␤-lactamase derived from TEM-2 that was produced by a strain of Proteus mirabilis. Since then, several IRT derivatives have been found in P. mirabilis (2, 5). IRT enzymes have also been found in Citrobacter freundii (29).We report on a novel plasmid-encoded IRT ␤-lactamase from a P. mirabilis clinical strain t...

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“…The first biochemical evidence of pore-forming colicin physically interacting with its immunity protein was reported by Espesset et al (1996), who showed that a colicin A poreforming domain, fused to a prokaryotic signal peptide (sppfColA), could be co-immunoprecipitated with its cognate epitope-tagged immunity protein (EpCai) (17). Using the same co-immunoprecipitation procedure, Nardi et al demonstrated that the smallest fragment of colicin A recognized by Cai was the hydrophobic helical hairpin (18).…”

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confidence: 99%

Channel Domain of Colicin A Modifies the Dimeric Organization of Its Immunity Protein

Zhang

Lloubès

Duché

2010

Journal of Biological Chemistry

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Proteins conferring immunity against pore-forming colicins are localized in the Escherichia coli inner membrane. Their protective effects are mediated by direct interaction with the C-terminal domain of their cognate colicins. Cai, the immunity protein protecting E. coli against colicin A, contains four cysteine residues. We report cysteine cross-linking experiments showing that Cai forms homodimers. Cai contains four transmembrane segments (TMSs), and dimerization occurs via the third TMS. Furthermore, we observe the formation of intramolecular disulfide bonds that connect TMS2 with either TMS1 or TMS3. Co-expression of Cai with its target, the colicin A pore-forming domain (pfColA), in the inner membrane prevents the formation of intermolecular and intramolecular disulfide bonds, indicating that pfColA interacts with the dimer of Cai and modifies its conformation. Finally, we show that when Cai is locked by disulfide bonds, it is no longer able to protect cells against exogenous added colicin A.Pore-forming colicins are plasmid-encoded bacteriocins, synthesized by Enterobacteriacae, that are lethal to other related strains. Like many toxins, colicins are organized into structural domains that perform different functions: the Nterminal and the central domains are involved in the transport through the Escherichia coli envelope, and the C-terminal domain carries the toxic activity of the protein (1).The three-dimensional structures of the soluble form of the pore-forming domains of colicins A, E1, Ia, B, and N share the same general architecture: a bundle of eight amphipathic ␣-helices surrounding two hydrophobic ␣-helices (H8ϩH9), completely buried within the protein (2-6). However, crystal structures do not reveal the structure of the channel in the membrane, which remains uncharacterized. The hydrophobic helical hairpin may be the primary attachment region for channel formation and channel opening and closing require insertion and extrusion of an amphipathic segment, which has not been precisely defined (7,8).Each colicin plasmid also encodes a specific immunity protein that protects the producing cell against the cytotoxic activity of its colicin. Immunity proteins are integral inner membrane proteins. They are classified into two groups according to sequence similarities: the A type (immunity proteins to colicins A, B, N, and U) and the E1 type (immunity proteins to colicins E1, 5, K, 10, Ia, and Ib) (9 -11). The colicin A immunity protein (Cai) 2 has four transmembrane segments (TMSs), and its N and C termini are in the cytoplasm (Fig. 1), whereas the immunity protein to colicin E1 (Cei) crosses the cytoplasmic membrane three times, with the N terminus located in the cytoplasm and the C terminus in the periplasm (10, 11).The immunity proteins to pore-forming colicins diffuse laterally in the membrane and interact with helices of the pore-forming domain of their cognate colicin just prior channel opening (12-15). Genetic studies of A-type colicins indicate that the main determinant recognized by the immuni...

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Colicin A Immunity Protein Interacts with the Hydrophobic Helical Hairpin of the Colicin A Channel Domain in the Escherichia coli Inner Membrane

Cited by 9 publications

References 20 publications

Colicin Biology

Colicin Biology

Integration of a Transposon Tn 1 -Encoded Inhibitor-Resistant β-Lactamase Gene, bla _TEM-67 from Proteus mirabilis , into the Escherichia coli Chromosome

Channel Domain of Colicin A Modifies the Dimeric Organization of Its Immunity Protein

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Colicin A Immunity Protein Interacts with the Hydrophobic Helical Hairpin of the Colicin A Channel Domain in the Escherichia coli Inner Membrane

Cited by 9 publications

References 20 publications

Colicin Biology

Colicin Biology

Integration of a Transposon Tn 1 -Encoded Inhibitor-Resistant β-Lactamase Gene, bla TEM-67 from Proteus mirabilis , into the Escherichia coli Chromosome

Channel Domain of Colicin A Modifies the Dimeric Organization of Its Immunity Protein

Contact Info

Product

Resources

About

Integration of a Transposon Tn 1 -Encoded Inhibitor-Resistant β-Lactamase Gene, bla _TEM-67 from Proteus mirabilis , into the Escherichia coli Chromosome