TY  - JOUR
A1  - Andres, Dorothee
A1  - Roske, Yvette
A1  - Doering, Carolin
A1  - Heinemann, Udo
A1  - Seckler, Robert
A1  - Barbirz, Stefanie
T1  - Tail morphology controls DNA release in two Salmonella phages with one lipopolysaccharide receptor recognition system
JF  - Molecular microbiology
N2  - Bacteriophages use specific tail proteins to recognize host cells. It is still not understood to molecular detail how the signal is transmitted over the tail to initiate infection. We have analysed in vitro DNA ejection in long-tailed siphovirus 9NA and short-tailed podovirus P22 upon incubation with Salmonella typhimurium lipopolysaccharide (LPS). We showed for the first time that LPS alone was sufficient to elicit DNA release from a siphovirus in vitro. Crystal structure analysis revealed that both phages use similar tailspike proteins for LPS recognition. Tailspike proteins hydrolyse LPS O antigen to position the phage on the cell surface. Thus we were able to compare in vitro DNA ejection processes from two phages with different morphologies with the same receptor under identical experimental conditions. Siphovirus 9NA ejected its DNA about 30 times faster than podovirus P22. DNA ejection is under control of the conformational opening of the particle and has a similar activation barrier in 9NA and P22. Our data suggest that tail morphology influences the efficiencies of particle opening given an identical initial receptor interaction event.
Y1  - 2012
U6  - https://doi.org/10.1111/j.1365-2958.2012.08006.x
SN  - 0950-382X
VL  - 83
IS  - 6
SP  - 1244
EP  - 1253
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Zaccheus, Mona V.
A1  - Bröker, Nina Kristin
A1  - Lundborg, Magnus
A1  - Uetrecht, Charlotte
A1  - Barbirz, Stefanie
A1  - Widmalm, Goran
T1  - Structural studies of the O-antigen polysaccharide from Escherichia coli TD2158 having O18 serogroup specificity and aspects of its interaction with the tailspike endoglycosidase of the infecting bacteriophage HK620
JF  - Carbohydrate research
N2  - We have analyzed the O-antigen polysaccharide of the previously uncharacterized Escherichia coli strain TD2158 which is a host of bacteriophage HK620. This bacteriophage recognizes and cleaves the polysaccharide with its tailspike protein (TSP). The polysaccharide preparation as well as oligosaccharides obtained from HK620TSP endoglycosidase digests were analyzed with NMR spectroscopy. Additionally, sugar analysis was performed on the O-antigen polysaccharide and MALDI-TOF MS was used in oligosaccharide analysis. The present study revealed a heterogeneous polysaccharide with a hexasaccharide repeating unit of the following structure:
 alpha-D-Glcp-(1 -> 6) vertical bar vertical bar 2)-alpha-L-Rhap-(1 -> 6)-alpha-D-Glcp-(1 -> 4)-alpha-D-Galp-(1 -> 3)-alpha-D-GlcpNAc- (1 ->vertical bar beta-D-Glcp/beta-D-GlcpNAc-(1 -> 3)
 A repeating unit with a D-GlcNAc substitution of D-Gal has been described earlier as characteristic for serogroup O18A1. Accordingly, we termed repeating units with D-Glc substitution at D-Gal as O18A2. NMR analyses of the polysaccharide confirmed that O18A1- and O18A2-type repeats were present in a 1:1 ratio. However, HK620TSP preferentially bound the D-GlcNAc- substituted O18A1-type repeating units in its high affinity binding pocket with a dissociation constant of 140 mu M and disfavored the O18A2-type having a beta-D-Glcp-(1 -> 3)-linked group. As a result, in hexasaccharide preparations, O18A1 and O18A2 repeats were present in a 9: 1 ratio stressing the clear preference of O18A1- type repeats to be cleaved by HK620TSP.
KW  - Escherichia coli
KW  - Tailspike
KW  - Endoglycosidase
KW  - Lipopolysaccharide
KW  - NMR
KW  - Mass spectrometry
Y1  - 2012
U6  - https://doi.org/10.1016/j.carres.2012.05.022
SN  - 0008-6215
VL  - 357
IS  - 8
SP  - 118
EP  - 125
PB  - Elsevier
CY  - Oxford
ER  -