Listeria monocytogenes DNA Glycosylase AdlP Affects Flagellar Motility, Biofilm Formation, Virulence, and Stress Responses.
The temperature-dependent alteration of flagellar motility gene expression is critical for the foodborne pathogen Listeria monocytogenes to respond to a changing environment. In this study, a genetic determinant, L. monocytogenes f2365_0220 (lmof2365_0220), encoding a putative protein that is structurally similar to the Bacillus cereus alkyl base DNA glycosylase (AlkD), was identified. This determinant was involved in the transcriptional repression of flagellar motility genes and was named adlP (encoding an AlkD-like protein [AdlP]). Deletion of adlP activated the expression of flagellar motility genes at 37°C and disrupted the temperature-dependent inhibition of L. monocytogenes motility. The adlP null strains demonstrated decreased survival in murine macrophage-like RAW264.7 cells and less virulence in mice. Furthermore, the deletion of adlP significantly decreased biofilm formation and impaired the survival of bacteria under several stress conditions, including the presence of a DNA alkylation compound (methyl methanesulfonate), an oxidative agent (H2O2), and aminoglycoside antibiotics. Our findings strongly suggest that adlP may encode a bifunctional protein that transcriptionally represses the expression of flagellar motility genes and influences stress responses through its DNA glycosylase activity.



We discovered a novel protein that we named AlkD-like protein (AdlP). This protein affected flagellar motility, biofilm formation, and virulence. Our data suggest that AdlP may be a bifunctional protein that represses flagellar motility genes and influences stress responses through its DNA glycosylase activity.
Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, Mississippi, USA.
Ting
T
Zhang
Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, Mississippi, USA.
Dongryeoul
D
Bae
Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, Mississippi, USA cw57@msstate.edu.
Chinling
C
Wang
D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D018441:Biofilms; D045647:DNA Glycosylases / Q000235:genetics / Q000378:metabolism*; D005260:Female; D005407:Flagella / Q000235:genetics / Q000502:physiology*; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008089:Listeria monocytogenes / Q000187:drug effects / Q000201:enzymology* / Q000472:pathogenicity* / Q000502:physiology; D008088:Listeriosis / Q000382:microbiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D013312:Stress, Physiological; D014774:Virulence
D001426:Bacterial Proteins; D006861:Hydrogen Peroxide; D045647:DNA Glycosylases