Choline-binding proteins (CBPs) from Streptococcus pneumoniae are involved in several important processes. Inactivation of zmpB, a gene that encodes a surface-located putative zinc metalloprotease, in a S. pneumoniae serotype 4 strain was recently reported to reveal a composite phenotype, including extensive chain formation, lysis defect and transformation deficiency. This phenotype was associated with the lack of surface expression of several CBPs, including the major autolysin LytA. LytA, normally 36 kDa in size, was reported to form an SDS-resistant 80 kDa complex with CinA. ZmpB was therefore proposed to control translocation of CBPs to the surface, possibly through the proteolytic release of CBPs (and RecA) from CinA. Based on the use of 12 independent mariner insertions in the zmpB gene of the well-characterized R6 laboratory strain, we could not confirm several of these observations. Our zmpB mutants: (i) did not form chains; (ii) lysed normally in the presence of deoxycholate, which indicates the presence of a functional autolysin; (iii) transformed at normal frequency; and (iv) contained bona fide CinA and LytA species. Polymorphism of ZmpB between R6 and the serotype 4 isolate could not account for the discrepancy, as inactivation of zmpB (through replacement by transposon-inactivated zmpB R6 alleles) in the latter strain did not affect separation of daughter cells and autolysis. The conflicting observations could be explained by our finding that the reportedly serotype 4 zmpB 'mutant' differed from its S. pneumoniae parent in lacking capsule and in exhibiting characteristic traits of the Streptococcus viridans group, including resistance to optochin.

Bergè, M., Garcia, P., Iannelli, F., Prère, M.F., Granadel, C., Polissi, A., et al. (2001). The puzzle of zmpB and extensive chain formation, autolysis defect and non-traslocation of choline-binding proteins in Streptococcus pneumoniae. MOLECULAR MICROBIOLOGY, 39(6), 1651-1660 [10.1046/j.1365-2958.2001.02359.x].

The puzzle of zmpB and extensive chain formation, autolysis defect and non-traslocation of choline-binding proteins in Streptococcus pneumoniae

IANNELLI F.;
2001-01-01

Abstract

Choline-binding proteins (CBPs) from Streptococcus pneumoniae are involved in several important processes. Inactivation of zmpB, a gene that encodes a surface-located putative zinc metalloprotease, in a S. pneumoniae serotype 4 strain was recently reported to reveal a composite phenotype, including extensive chain formation, lysis defect and transformation deficiency. This phenotype was associated with the lack of surface expression of several CBPs, including the major autolysin LytA. LytA, normally 36 kDa in size, was reported to form an SDS-resistant 80 kDa complex with CinA. ZmpB was therefore proposed to control translocation of CBPs to the surface, possibly through the proteolytic release of CBPs (and RecA) from CinA. Based on the use of 12 independent mariner insertions in the zmpB gene of the well-characterized R6 laboratory strain, we could not confirm several of these observations. Our zmpB mutants: (i) did not form chains; (ii) lysed normally in the presence of deoxycholate, which indicates the presence of a functional autolysin; (iii) transformed at normal frequency; and (iv) contained bona fide CinA and LytA species. Polymorphism of ZmpB between R6 and the serotype 4 isolate could not account for the discrepancy, as inactivation of zmpB (through replacement by transposon-inactivated zmpB R6 alleles) in the latter strain did not affect separation of daughter cells and autolysis. The conflicting observations could be explained by our finding that the reportedly serotype 4 zmpB 'mutant' differed from its S. pneumoniae parent in lacking capsule and in exhibiting characteristic traits of the Streptococcus viridans group, including resistance to optochin.
2001
Bergè, M., Garcia, P., Iannelli, F., Prère, M.F., Granadel, C., Polissi, A., et al. (2001). The puzzle of zmpB and extensive chain formation, autolysis defect and non-traslocation of choline-binding proteins in Streptococcus pneumoniae. MOLECULAR MICROBIOLOGY, 39(6), 1651-1660 [10.1046/j.1365-2958.2001.02359.x].
File in questo prodotto:
File Dimensione Formato  
2001 Bergè et al Molecular Microbiology.pdf

accesso aperto

Tipologia: PDF editoriale
Licenza: PUBBLICO - Pubblico con Copyright
Dimensione 663.52 kB
Formato Adobe PDF
663.52 kB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11365/34789
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo