Structural engineering of a phage lysin that targets gram-negative pathogens.
Bacterial pathogens are becoming increasingly resistant to antibiotics. As an alternative therapeutic strategy, phage therapy reagents containing purified viral lysins have been developed against gram-positive organisms but not against gram-negative organisms due to the inability of these types of drugs to cross the bacterial outer membrane. We solved the crystal structures of a Yersinia pestis outer membrane transporter called FyuA and a bacterial toxin called pesticin that targets this transporter. FyuA is a β-barrel membrane protein belonging to the family of TonB dependent transporters, whereas pesticin is a soluble protein with two domains, one that binds to FyuA and another that is structurally similar to phage T4 lysozyme. The structure of pesticin allowed us to design a phage therapy reagent comprised of the FyuA binding domain of pesticin fused to the N-terminus of T4 lysozyme. This hybrid toxin kills specific Yersinia and pathogenic E. coli strains and, importantly, can evade the pesticin immunity protein (Pim) giving it a distinct advantage over pesticin. Furthermore, because FyuA is required for virulence and is more common in pathogenic bacteria, the hybrid toxin also has the advantage of targeting primarily disease-causing bacteria rather than indiscriminately eliminating natural gut flora.
Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
Petra
P
Lukacik
Travis J
TJ
Barnard
Paul W
PW
Keller
Kaveri S
KS
Chaturvedi
Nadir
N
Seddiki
James W
JW
Fairman
Nicholas
N
Noinaj
Tara L
TL
Kirby
Jeffrey P
JP
Henderson
Alasdair C
AC
Steven
B Joseph
BJ
Hinnebusch
Susan K
SK
Buchanan
D001426:Bacterial Proteins / Q000737:chemistry; D001430:Bacteriocins / Q000737:chemistry; D001435:Bacteriophages / Q000378:metabolism* / Q000502:physiology; D002462:Cell Membrane / Q000378:metabolism; D020285:Cryoelectron Microscopy; D006090:Gram-Negative Bacteria / Q000821:virology*; D008958:Models, Molecular; D009088:Mucoproteins / Q000737:chemistry / Q000378:metabolism*; D011487:Protein Conformation; D015202:Protein Engineering; D021381:Protein Transport; D011956:Receptors, Cell Surface / Q000737:chemistry
D001426:Bacterial Proteins; D001430:Bacteriocins; C090748:FyuA protein, Yersinia; D009088:Mucoproteins; D011956:Receptors, Cell Surface; C010393:lysin, gastropoda; C011330:Pesticin