Molecular cloning and characterization of a 35.5-kilodalton lipoprotein of Treponema pallidum.
A clone expressing a 35.5-kDa recombinant treponemal protein was isolated from a genomic DNA library constructed from Treponema pallidum street strain 14. Polyclonal antiserum raised against the recombinant protein reacted with a corresponding native protein of comparable size in T. pallidum that is specific to the pathogenic treponemes. Radiolabeling of the recombinant protein with [3H]palmitate demonstrated that it is lipid modified. Like other recently characterized T. pallidum lipoproteins, the 35.5-kDa lipoprotein partitioned into the detergent phase from T. pallidum cells fractionated with Triton X-114, suggesting that it is an integral membrane protein. Processing of the recombinant 35.5-kDa lipoprotein from a precursor form to a smaller mature form was not evident in pulse-chase experiments. However, pretreatment of Escherichia coli cells expressing the 35.5-kDa lipoprotein with inhibitors of protein processing or translocation revealed the existence of a higher-molecular-mass precursor. Gene fusion studies with the transposon TnphoA demonstrated the presence of an export signal in the 35.5-kDa lipoprotein that promotes the extracytoplasmic localization of a 35.5-kDa lipoprotein-PhoA hybrid.
Hubbard
C L
CL
Department of Parasitology, School of Public Health, University of North Carolina, Chapel Hill 27599-7400.
Gherardini
F C
FC
Bassford
P J
PJ
Stamm
L V
LV
D000469:Alkaline Phosphatase / Q000235:genetics; D000818:Animals; D001428:Bacterial Vaccines / Q000276:immunology; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D004251:DNA Transposable Elements; D004926:Escherichia coli / Q000032:analysis; D006801:Humans; D007106:Immune Sera / Q000276:immunology; D008074:Lipoproteins / Q000235:genetics* / Q000276:immunology / Q000302:isolation & purification; D008297:Male; D008565:Membrane Proteins / Q000032:analysis; D008970:Molecular Weight; D010168:Palmitates / Q000378:metabolism; D011817:Rabbits; D011994:Recombinant Proteins / Q000276:immunology; D014210:Treponema pallidum / Q000032:analysis* / Q000276:immunology
D001428:Bacterial Vaccines; D004251:DNA Transposable Elements; D007106:Immune Sera; D008074:Lipoproteins; D008565:Membrane Proteins; D010168:Palmitates; D011994:Recombinant Proteins; D000469:Alkaline Phosphatase