Faculty Opinions recommendation of DNA as a nutrient: novel role for bacterial competence gene homologs.

2002 ◽  
Author(s):  
Jorge Escalante-Semerena
Keyword(s):  
Competence Gene

scholarly journals Mechanisms controlling competence gene expression in murine fibroblasts stimulated with minimally modified LDL.

1992 ◽  
Vol 12 (7) ◽  
pp. 800-806 ◽  
Author(s):  
R W Bork ◽  
K L Svenson ◽  
M Mehrabian ◽  
A J Lusis ◽  
A M Fogelman ◽  
...  
Keyword(s):  
Gene Expression ◽  
Competence Gene ◽  
Modified Ldl ◽  
Murine Fibroblasts

scholarly journals Unleashing Natural Competence in Lactococcus lactis by Induction of the Competence Regulator ComX

2017 ◽  
Vol 83 (20) ◽  
Author(s):  
Joyce Mulder ◽  
Michiel Wels ◽  
Oscar P. Kuipers ◽  
Michiel Kleerebezem ◽  
Peter A. Bron
Keyword(s):  
Lactococcus Lactis ◽  
Genetic Manipulation ◽  
Bacterial Species ◽  
Streptococcus Thermophilus ◽  
Starter Cultures ◽  
Natural Competence ◽  
Content Type ◽  
Competence Gene ◽  
Gene Sets ◽  
Novel Traits

ABSTRACT In biotechnological workhorses like Streptococcus thermophilus and Bacillus subtilis, natural competence can be induced, which facilitates genetic manipulation of these microbes. However, in strains of the important dairy starter Lactococcus lactis, natural competence has not been established to date. However, in silico analysis of the complete genome sequences of 43 L. lactis strains revealed complete late competence gene sets in 2 L. lactis subsp. cremoris strains (KW2 and KW10) and at least 10 L. lactis subsp. lactis strains, including the model strain IL1403 and the plant-derived strain KF147. The remainder of the strains, including all dairy isolates, displayed genomic decay in one or more of the late competence genes. Nisin-controlled expression of the competence regulator comX in L. lactis subsp. lactis KF147 resulted in the induction of expression of the canonical competence regulon and elicited a state of natural competence in this strain. In contrast, comX expression in L. lactis NZ9000, which was predicted to encode an incomplete competence gene set, failed to induce natural competence. Moreover, mutagenesis of the comEA-EC operon in strain KF147 abolished the comX-driven natural competence, underlining the involvement of the competence machinery. Finally, introduction of nisin-inducible comX expression into nisRK-harboring derivatives of strains IL1403 and KW2 allowed the induction of natural competence in these strains also, expanding this phenotype to other L. lactis strains of both subspecies. IMPORTANCE Specific bacterial species are able to enter a state of natural competence in which DNA is taken up from the environment, allowing the introduction of novel traits. Strains of the species Lactococcus lactis are very important starter cultures for the fermentation of milk in the cheese production process, where these bacteria contribute to the flavor and texture of the end product. The activation of natural competence in this industrially relevant organism can accelerate research aiming to understand industrially relevant traits of these bacteria and can facilitate engineering strategies to harness the natural biodiversity of the species in optimized starter strains.

scholarly journals Genetic Diversity of Competence Gene Loci in Clinical Genotypes of Streptococcus mutans

2006 ◽  
Vol 44 (8) ◽  
pp. 3015-3020 ◽  
Author(s):  
M. I. Klein ◽  
S. Bang ◽  
F. M. Florio ◽  
J. F. Hofling ◽  
R. B. Goncalves ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Streptococcus Mutans ◽  
Competence Gene

scholarly journals Unleashing natural competence inLactococcus lactisby induction of the competence regulator ComX

2017 ◽  
Author(s):  
Joyce Mulder ◽  
Michiel Wels ◽  
Oscar P. Kuipers ◽  
Michiel Kleerebezem ◽  
Peter A. Bron
Keyword(s):  
Lactococcus Lactis ◽  
Genetic Manipulation ◽  
Bacterial Species ◽  
Streptococcus Thermophilus ◽  
Starter Cultures ◽  
Natural Competence ◽  
Competence Gene ◽  
Gene Sets ◽  
Novel Traits ◽  
Derivatives Of

AbstractIn biotechnological work horses likeStreptococcus thermophilusandBacillus subtilisnatural competence can be induced, which facilitates genetic manipulation of these microbes. However, in strains of the important dairy starterLactococcus lactisnatural competence has not been established to date. However,in silicoanalysis of complete genome sequences of 43L. lactisstrains revealed complete late-competence gene-sets in 2L. lactissubspeciescremorisstrains (KW2 and KW10) and 8L. lactissubspecieslactisstrains, including the model strain IL1403 and the plant-derived strain KF147. The remainder of the strains, including all dairy isolates, displayed genomic decay in one or more of the late competence genes. Nisin-controlled expression of the competence regulatorcomXinL. lactissubsp.lactisKF147 resulted in the induction of expression of the canonical competence regulon, and elicited a state of natural competence in this strain. By contrast,comXexpression inL. lactisNZ9000, predicted to encode an incomplete competence gene-set, failed to induce natural competence. Moreover, mutagenesis of thecomEA-ECoperon in strain KF147, abolished thecomXdriven natural competence, underpinning the involvement of the competence machinery. Finally, introduction of nisin-induciblecomXexpression intonisRK-harboring derivatives of strains IL1403 and KW2 allowed the induction of natural competence also in these strains, expanding this phenotype to otherL. lactisstrains of both subspecies.Significance statementSpecific bacterial species are able to enter a state of natural competence in which DNA is taken up from the environment, allowing the introduction of novel traits. Strains of the speciesLactococcus lactisare very important starter cultures for the fermentation of milk in the cheese production process, where these bacteria contribute to the flavor and texture of the end-product. The activation of natural competence in this industrially relevant organism can accelerate research aiming to understand industrially relevant traits of these bacteria, and can facilitate engineering strategies to harness the natural biodiversity of the species in optimized starter strains.

scholarly journals Identification and Characterization of a Novel Competence Gene,comC, Required for DNA Binding and Uptake inAcinetobacter sp. Strain BD413

1998 ◽  
Vol 180 (6) ◽  
pp. 1592-1595 ◽  
Author(s):  
Caroline Link ◽  
Sandra Eickernjäger ◽  
Dirk Porstendörfer ◽  
Beate Averhoff
Keyword(s):  
Electron Microscopy ◽  
Dna Binding ◽  
Natural Transformation ◽  
Leader Sequence ◽  
Wild Type ◽  
Type Iv Pilus ◽  
Competence Gene ◽  
Type Iv ◽  
Identification And Characterization

ABSTRACT A gene (comC) essential for natural transformation was identified in Acinetobacter sp. strain BD413. ComC has a typical leader sequence and is similar to different type IV pilus assembly factors. A comC mutant (T308) is not able to bind or take up DNA but exhibits a piliation phenotype indistinguishable from the transformation wild type as revealed by electron microscopy.

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