This Article Full Text Full Text (PDF) Supplemental material Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Tomita, H. Articles by Ike, Y. Search for Related Content PubMed PubMed Citation Articles by Tomita, H. Articles by Ike, Y.

 Previous Article  |  Next Article 

Journal of Bacteriology, March 2008, p. 2075-2085, Vol. 190, No. 6
0021-9193/08/$08.00+0     doi:10.1128/JB.01056-07
Copyright © 2008, American Society for Microbiology. All Rights Reserved.

Cloning and Genetic Analyses of the Bacteriocin 41 Determinant Encoded on the Enterococcus faecalis Pheromone-Responsive Conjugative Plasmid pYI14: a Novel Bacteriocin Complemented by Two Extracellular Components (Lysin and Activator) ^,

Haruyoshi Tomita,¹ Elizabeth Kamei,¹ and Yasuyoshi Ike^1,2*

Department of Bacteriology and Bacterial Infection Control,¹ Laboratory of Bacterial Drug Resistance, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan²

Received 5 July 2007/ Accepted 4 January 2008

The conjugative plasmid pYI14 (61 kbp) was isolated from Enterococcus faecalis YI714, a clinical isolate. pYI14 conferred a pheromone response on its host and encoded bacteriocin 41 (bac41). Bacteriocin 41 (Bac41) only showed activity against E. faecalis. Physical mapping of pYI14 showed that it consisted of EcoRI fragments A to P. The clone pHT1100, containing EcoRI fragments A (12.6 kbp) and H (3.5 kbp), conferred the bacteriocin activity on E. faecalis strains. Genetic analysis showed that the determinant was located in a 6.6-kbp region within the EcoRI AH fragments. Six open reading frames (ORFs) were identified in this region and designated ORF7 (bacL₁) ORF8 (bacL₂), ORF9, ORF10, ORF11 (bacA), and ORF12 (bacI). They were aligned in this order and oriented in the same direction. ORFs bacL₁, bacL₂, bacA, and bacI were essential for expression of the bacteriocin in E. faecalis. Extracellular complementation of bacteriocin expression was possible for bacL₁ and -L₂ and bacA mutants. bacL₁ and -L₂ and bacA encoded bacteriocin component L and activator component A, respectively. The products of these genes are secreted into the culture medium and extracellularly complement bacteriocin expression. bacI encoded immunity, providing the host with resistance to its own bacteriocin activity. The bacL₁-encoded protein had significant homology with lytic enzymes that attack the gram-positive bacterial cell wall. Sequence data for the deduced bacL₁-encoded protein suggested that it has a domain structure consisting of an N-terminal signal peptide, a second domain with the enzymatic activity, and a third domain with a three-repeat structure directing the proenzyme to its cell surface receptor.

---

* Corresponding author. Mailing address: Department of Bacteriology and Bacterial Infection Control, Gunma University Graduate School of Medicine, Showa-machi 3-39-22, Maebashi, Gunma 371-8511, Japan. Phone: 81-27-220-7990. Fax: 81-27-220-7996. E-mail: yasuike{at}med.gunma-u.ac.jp

Published ahead of print on 18 January 2008.

Supplemental material for this article may be found at http://jb.asm.org/.

---

Journal of Bacteriology, March 2008, p. 2075-2085, Vol. 190, No. 6
0021-9193/08/$08.00+0     doi:10.1128/JB.01056-07
Copyright © 2008, American Society for Microbiology. All Rights Reserved.

This article has been cited by other articles:

• Zheng, B., Tomita, H., Inoue, T., Ike, Y. (2009). Isolation of VanB-Type Enterococcus faecalis Strains from Nosocomial Infections: First Report of the Isolation and Identification of the Pheromone-Responsive Plasmids pMG2200, Encoding VanB-Type Vancomycin Resistance and a Bac41-Type Bacteriocin, and pMG2201, Encoding Erythromycin Resistance and Cytolysin (Hly/Bac). Antimicrob. Agents Chemother. 53: 735-747 [Abstract] [Full Text]