Functional analysis of D-alanylation of lipoteichoic acid in the probiotic strain Lactobacillus rhamnosus GG.
Lipoteichoic acid (LTA) is a macroamphiphile molecule which performs several functions in gram-positive bacteria, such as maintenance of cell wall homeostasis. D-alanylation of LTA requires the proteins encoded by the dlt operon, and this process is directly related to the charge properties of this polymer strongly contributing to its function. The insertional inactivation of dltD of the probiotic strain Lactobacillus rhamnosus GG (ATCC 53103) resulted in the complete absence of D-alanyl esters in the LTA as confirmed by nuclear magnetic resonance analysis. This was reflected in modifications of the bacterial cell surface properties. The dltD strain showed 2.4-fold-increased cell length, a low survival capacity in response to gastric juice challenge, an increased sensitivity to human beta-defensin-2, an increased rate of autolysis, an increased capacity to initiate growth in the presence of an anionic detergent, and a decreased capacity to initiate growth in the presence of cationic peptides compared to wild-type results. However, in vitro experiments revealed no major differences for adhesion to human intestinal epithelial cells, biofilm formation, and immunomodulation. These properties are considered to be important for probiotics. The role of the dlt operon in lactobacilli is discussed in view of these results.
Perea Vélez
Mónica
M
Centre of Microbial and Plant Genetics, Katholieke Universiteit Leuven, Kasteelpark Arenberg 20, 3001 Leuven, Belgium.
Verhoeven
Tine L A
TL
Draing
Christian
C
Von Aulock
Sonja
S
Pfitzenmaier
Markus
M
Geyer
Armin
A
Lambrichts
Ivo
I
Grangette
Corinne
C
Pot
Bruno
B
Vanderleyden
Jos
J
De Keersmaecker
Sigrid C J
SC
D000409:Alanine / Q000378:metabolism*; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001422:Bacterial Adhesion / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics; D001433:Bacteriolysis / Q000235:genetics; D018441:Biofilms / Q000254:growth & development; D002460:Cell Line; D002473:Cell Wall / Q000737:chemistry / Q000378:metabolism; D016207:Cytokines / Q000276:immunology; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004847:Epithelial Cells / Q000276:immunology / Q000382:microbiology; D005750:Gastric Juice / Q000382:microbiology; D017353:Gene Deletion; D006801:Humans; D052201:Lacticaseibacillus rhamnosus / Q000187:drug effects / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000737:chemistry / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D050296:Microbial Viability / Q000235:genetics; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D009561:Nisin / Q000494:pharmacology; D011112:Polymyxin B / Q000494:pharmacology; D019936:Probiotics / Q000737:chemistry / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D013682:Teichoic Acids / Q000737:chemistry / Q000378:metabolism*; D013869:Thiolester Hydrolases / Q000235:genetics; D023083:beta-Defensins / Q000276:immunology
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D016207:Cytokines; C106641:DEFB4A protein, human; D004269:DNA, Bacterial; D008070:Lipopolysaccharides; D013682:Teichoic Acids; D023083:beta-Defensins; D009561:Nisin; C009900:lipoteichoic acid; C408973:DltD protein, bacteria; D013869:Thiolester Hydrolases; D011112:Polymyxin B; D000409:Alanine