The cell wall-associated serine protease PrtA: a highly conserved virulence factor of Streptococcus pneumoniae.
The surface-associated subtilisin-like serine protease PrtA was identified by screening a genomic expression library from Streptococcus pneumoniae using a convalescent-phase serum. In Western blot analysis two forms of PrtA were detected in whole cell lysate and a truncated form only in culture supernatant suggesting that PrtA is produced as a precursor protein, translocated to the cell surface, truncated, and released into the surroundings. A 5' fragment of the gene was found highly conserved among 78 pneumococcal isolates of clinical relevance. Immunogenicity of PrtA, limited genetic variation, and the involvement in pneumococcal virulence demonstrated in in vivo experiments might identify PrtA as a promising candidate for a protein based vaccine.
Bethe
G
G
Department of Medical Microbiology and Virology, University of Düsseldorf, Geb. 22.21/U1, Universitätsstrasse 1, D-40225 Düsseldorf, Germany.
Nau
R
R
Wellmer
A
A
Hakenbeck
R
R
Reinert
R R
RR
Heinz
H P
HP
Zysk
G
G
D000595:Amino Acid Sequence; D000818:Animals; D002473:Cell Wall / Q000201:enzymology*; D017124:Conserved Sequence; D006801:Humans; D008666:Metalloendopeptidases / Q000235:genetics* / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D011008:Pneumococcal Infections / Q000382:microbiology* / Q000401:mortality; D017422:Sequence Analysis, DNA; D012697:Serine Endopeptidases / Q000235:genetics / Q000378:metabolism; D013296:Streptococcus pneumoniae / Q000201:enzymology* / Q000472:pathogenicity*; D014774:Virulence
D012697:Serine Endopeptidases; D008666:Metalloendopeptidases; C079508:PrtA metalloprotease