title: Extracellular targeting of choline-binding proteins in Streptococcus pneumoniae by a zinc metalloprotease.
abstract: A genetic-based search for surface proteins of Streptococcus pneumoniae involved in adhesion identified a putative zinc metalloprotease (ZmpB). ZmpB shared high amino acid sequence similarities with IgA1 proteases of Gram-positive bacteria, but ZmpB had neither IgA1 nor IgA2 protease activity. Analysis of a family of surface-expressed proteins, the choline-binding proteins (Cbp's), in a zmpB-deficient mutant demonstrated a global loss of surface expression of CbpA, CbpE, CbpF and CbpJ. CbpA was detected within the cytoplasm. The zmpB-deficient mutant also failed to lyse with penicillin, a sign of lack of function of the Cbp LytA. Immunodetection studies revealed that the autolysin (LytA), normally located on the cell wall, was trapped in the cytoplasm colocalized with DNA and the transformation protein CinA. Trafficking of CinA and RecA to the cell membrane during genetic competence was also not observed in the zmpB-deficient mutant. These results suggest a protease dependent regulatory mechanism governing the translocation of CinA and the Cbp's LytA and CbpA of S. pneumoniae.
authors.affiliation: Department of Infectious Diseases, St. Jude Children's Research Hospital, 332 N. Lauderdale St., Memphis, TN 38105, USA.
authors.forename: R
authors.initials: R
authors.lastname: Novak
authors.forename: E
authors.initials: E
authors.lastname: Charpentier
authors.forename: J S
authors.initials: JS
authors.lastname: Braun
authors.forename: E
authors.initials: E
authors.lastname: Park
authors.forename: S
authors.initials: S
authors.lastname: Murti
authors.forename: E
authors.initials: E
authors.lastname: Tuomanen
authors.forename: R
authors.initials: R
authors.lastname: Masure
mesh_terms: D000483:Alleles; D000818:Animals; D001329:Autolysis; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002794:Choline / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism; D004798:Enzymes / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D006360:Heat-Shock Proteins / Q000378:metabolism; D008666:Metalloendopeptidases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D009238:N-Acetylmuramoyl-L-alanine Amidase; D011008:Pneumococcal Infections / Q000382:microbiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction; D013296:Streptococcus pneumoniae / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity; D013347:Subcellular Fractions; D014169:Transformation, Bacterial; D015032:Zinc
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; C490083:CbpA protein, bacteria; D004268:DNA-Binding Proteins; D004798:Enzymes; D006360:Heat-Shock Proteins; C412019:ZmpB enzyme; D008666:Metalloendopeptidases; D009238:N-Acetylmuramoyl-L-alanine Amidase; D015032:Zinc; D002794:Choline