Identification and characterization of a novel heme-associated cell surface protein made by Streptococcus pyogenes.
Analysis of the genome sequence of a serotype M1 group A Streptococcus (GAS) strain identified a gene encoding a previously undescribed putative cell surface protein. The gene was cloned from a serotype M1 strain, and the recombinant protein was overexpressed in Escherichia coli and purified to homogeneity. The purified protein was associated with heme in a 1:1 stoichiometry. This streptococcal heme-associated protein, designated Shp, was produced in vitro by GAS, located on the bacterial cell surface, and accessible to specific antibody raised against the purified recombinant protein. Mice inoculated subcutaneously with GAS and humans with invasive infections and pharyngitis caused by GAS seroconverted to Shp, indicating that Shp was produced in vivo. The blood of mice actively immunized with Shp had significantly higher bactericidal activity than the blood of unimmunized mice. The shp gene was cotranscribed with eight contiguous genes, including homologues of an ABC transporter involved in iron uptake in gram-negative bacteria. Our results indicate that Shp is a novel cell surface heme-associated protein.
Lei
Benfang
B
Laboratory of Human Bacterial Pathogenesis, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana 59840, USA.
Smoot
Laura M
LM
Menning
Heather M
HM
Voyich
Jovanka M
JM
Kala
Subbarao V
SV
Deleo
Frank R
FR
Reid
Sean D
SD
Musser
James M
JM
D000818:Animals; D001425:Bacterial Outer Membrane Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D001428:Bacterial Vaccines / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D002352:Carrier Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D002462:Cell Membrane / Q000378:metabolism; D005260:Female; D005798:Genes, Bacterial; D000081062:Heme-Binding Proteins; D006420:Hemeproteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D006801:Humans; D007501:Iron; D051379:Mice; D012329:RNA, Bacterial; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D013290:Streptococcal Infections / Q000276:immunology / Q000517:prevention & control*; D013297:Streptococcus pyogenes / Q000235:genetics / Q000276:immunology*; D014158:Transcription, Genetic; D014611:Vaccination; D014614:Vaccines, Synthetic / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*
D001425:Bacterial Outer Membrane Proteins; D001428:Bacterial Vaccines; D002352:Carrier Proteins; D000081062:Heme-Binding Proteins; D006420:Hemeproteins; D012329:RNA, Bacterial; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D014614:Vaccines, Synthetic; D007501:Iron