| Title: | The incongruent gelatinase genotype and phenotype in Enterococcus faecalis are due to shutting off the ability to respond to the gelatinase biosynthesis-activating pheromone (GBAP) quorum-sensing signal |
| Author(s): | Teixeira N; Santos S; Marujo P; Yokohata R; Iyer VS; Nakayama J; Hancock LE; Serror P; Silva Lopes MF; |
| Address: | "IBET, Quinta do Marques, Estacao Agronomica Nacional, Apartado 12, 2781-901 Oeiras, Portugal. Instituto de Tecnologia Quimica e Biologica, Universidade Nova de Lisboa, Apartado 127, 2781-901 Oeiras, Portugal. Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan. Division of Biology, Kansas State University, 19 Ackert Hall, Manhattan, KS 66506, USA. AgroParisTech, UMR Micalis, F-78350 Jouy-en-Josas, France. INRA, UMR1319 Micalis, F-78350 Jouy-en-Josas, France" |
| ISSN/ISBN: | 1465-2080 (Electronic) 1350-0872 (Print) 1350-0872 (Linking) |
| Abstract: | "The concomitant presence of a complete fsr quorum-sensing system and gelE-sprE operons in Enterococcus faecalis is known to be essential for the detection of gelatinase activity. However, there are reports of the absence of gelatinase activity despite the presence of complete fsr and gelE loci. In order to understand this incongruence between genotype and phenotype we sequenced fsr and gelE loci of the E. faecalis LN68 strain, which was previously found to carry both operons but to lack gelatinase activity. Of the 59 nucleotide differences detected compared with the gelatinase-positive V583 strain, we found a nonsense mutation (a premature STOP codon) predicted to truncate the ATPase sensor domain of the FsrC protein, responsible for sensing and transducing the signal from the quorum-sensing molecule. Strain LN68 was highly affected in the expression of the gelE and sprE genes, further supporting the lack of Fsr-dependent gelE induction. When we constructed a V583 mutant with the same premature stop mutation in the fsrC gene the resulting strain was no longer able to degrade gelatin. We conclude that the reduced ability to transduce the quorum-sensing signal of the prematurely truncated FsrC protein is sufficient to explain the negative gelatinase phenotype. As the incongruent genotype and phenotype is detected in natural isolates, we believe that the silencing of the quorum-sensing system Fsr may be beneficial for some E. faecalis strains" |
| Keywords: | "Amino Acid Sequence Bacterial Proteins/genetics/*metabolism Base Sequence Enterococcus faecalis/*enzymology/genetics/physiology Gelatinases/genetics/*metabolism Gene Expression Regulation, Bacterial Genotype Lactones/*metabolism Molecular Sequence Data Pe;" |
| Notes: | "MedlineTeixeira, Neuza Santos, Sofia Marujo, Paulo Yokohata, Ryoji Iyer, Vijayalakshmi S Nakayama, Jiro Hancock, Lynn E Serror, Pascale Silva Lopes, Maria de Fatima eng R01 AI077782/AI/NIAID NIH HHS/ Research Support, Non-U.S. Gov't England 2011/11/26 Microbiology (Reading). 2012 Feb; 158(Pt 2):519-528. doi: 10.1099/mic.0.055574-0. Epub 2011 Nov 24" |
