Author | dc.contributor.author | Carter Jaña, Javier Antonio | |
Author | dc.contributor.author | Blondel, Carlos | es_CL |
Author | dc.contributor.author | Zaldívar San Román, María Mercedes | es_CL |
Author | dc.contributor.author | Álvarez Armijo, Sergio Aníbal | es_CL |
Author | dc.contributor.author | Marolda, Cristina L. | es_CL |
Author | dc.contributor.author | Valvano, Miguel A. | es_CL |
Author | dc.contributor.author | Contreras, Inés | es_CL |
Admission date | dc.date.accessioned | 2009-08-13T16:43:59Z | |
Available date | dc.date.available | 2009-08-13T16:43:59Z | |
Publication date | dc.date.issued | 2007-10 | |
Cita de ítem | dc.identifier.citation | MICROBIOLOGY-SGM 153: 3499-3507 Part: 10 | en |
Identifier | dc.identifier.issn | 1350-0872 | |
Identifier | dc.identifier.uri | https://repositorio.uchile.cl/handle/2250/120760 | |
Abstract | dc.description.abstract | Shigella flexneri 2a 2457T produces lipopolysaccharide (LIPS) with two O-antigen (OAg) chain lengths: a short (S-OAg) controlled by WzzB and a very long (VL-OAg) determined by Wzz(pHS-2). This study demonstrates that the synthesis and length distribution of the S. flexneri OAg are under growth-phase-dependent regulation. Quantitative electrophoretic analysis showed that the VL-OAg increased during growth while the S-OAg distribution remained constant. Increased production of VL-OAg correlated with the growth-phase-regulated expression of the transcription elongation factor RfaH, and was severely impaired in a Delta rfaH mutant, which synthesized only low-molecular-mass OAg molecules and a small amount of S-OAg. Real-time RT-PCR revealed a drastic reduction of wzy polymerase gene expression in the Delta rfaH mutant. Complementation of this mutant with the wzy gene cloned into a high-copy-number plasmid restored the bimodal OAg distribution, suggesting that cellular levels of Wzy influence not only OAg polymerization but also chain-length distribution. Accordingly, overexpression of wzy in the wild-type strain resulted in production of a large amount of high-molecular-mass OAg molecules. An increased dosage of either wzzB or wzz(pHS-2) also altered OAg chain-length distribution. Transcription of wzzB and wzzpHS-2 genes was regulated during bacterial growth but in an RfaH-independent manner. Overall, these findings indicate that expression of the wzy, wzzB and wzz(pHS-2) genes is finely regulated to determine an appropriate balance between the proteins responsible for polymerization and chain-length distribution of S. flexneri OAg. | en |
Lenguage | dc.language.iso | en | en |
Publisher | dc.publisher | SOC GENERAL MICROBIOLOGY | en |
Keywords | dc.subject | ENTERICA SEROVAR TYPHI | en |
Título | dc.title | O-antigen modal chain length in Shigella flexneri 2a is growth-regulated through RfaH-mediated transcriptional control of the wzy gene | en |
Document type | dc.type | Artículo de revista | |