The C-terminal domain of the secretin PulD contains the binding site for its cognate chaperone, PulS, and confers PulS dependence on pIVf1 function.
Related outer membrane proteins, termed secretins, participate in the secretion of macromolecules across the outer membrane of many Gram-negative bacteria. In the pullulanase-secretion system, PulS, an outer membrane-associated lipoprotein, is required both for the integrity and the proper outer membrane localization of the PulD secretin. Here we show that the PulS-binding site is located within the C-terminal 65 residues of PulD. Addition of this domain to the filamentous phage secretin, pIV, or to the unrelated maltose-binding protein rendered both proteins dependent on PulS for stability. A chimeric protein composed of bacteriophage f1 pIV and the C-terminal domain of PuID required properly localized PulS to support phage assembly. An in vivo complex formed between the pIV-PulD65 chimera and PulS was detected by co-immunoprecipitation and by affinity chromatography.
Daefler
S
S
Rockefeller University, New York, New York 10021, USA.
Guilvout
I
I
Hardie
K R
KR
Pugsley
A P
AP
Russel
M
M
D000595:Amino Acid Sequence; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000096:biosynthesis; D001435:Bacteriophages / Q000254:growth & development / Q000378:metabolism; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D017931:DNA Primers / Q000235:genetics; D006026:Glycoside Hydrolases / Q000378:metabolism; D006090:Gram-Negative Bacteria / Q000235:genetics / Q000378:metabolism / Q000821:virology; D006360:Heat-Shock Proteins / Q000096:biosynthesis; D018832:Molecular Chaperones / Q000378:metabolism*; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012633:Secretin / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid
D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D017931:DNA Primers; D006360:Heat-Shock Proteins; D018832:Molecular Chaperones; C069816:phage shock protein, Bacteria; C061377:PulD protein, Klebsiella pneumoniae; D012633:Secretin; D006026:Glycoside Hydrolases; C100181:pullulanase