Artículo
NtcA-regulated heterocyst differentiation genes hetC and devB from Anabaena sp. strain PCC 7120 exhibit a similar tandem promoter arrangement
Autor/es | Muro Pastor, María Isabel
Flores García, Enrique Herrero Moreno, Antonia |
Departamento | Universidad de Sevilla. Departamento de Bioquímica Vegetal y Biología Molecular |
Fecha de publicación | 2009 |
Fecha de depósito | 2017-07-21 |
Publicado en |
|
Resumen | Transcription of the hetC gene, whose product is required for heterocyst differentiation, takes place from a long promoter region that includes the previously described HetR-independent, NtcA-activated promoter producing ... Transcription of the hetC gene, whose product is required for heterocyst differentiation, takes place from a long promoter region that includes the previously described HetR-independent, NtcA-activated promoter producing transcripts with a 5′ end corresponding to position -571 with respect to the translational start site of hetC. Northern blot analysis indicated that the accumulation of hetC transcripts depends on HetR, and a second transcriptional start site located at position -293 that leads to NtcA-dependent, HetR-dependent inducible transcription of hetC was identified. Upon nitrogen stepdown, expression of a PhetC::gfp fusion was transiently induced in specific cells that were differentiating into heterocysts, both when the whole promoter region (containing transcription start points -571 and -293) or a short version (containing only the transcription start point -293) was used. Expression of hetC from the -293 position was delayed in a strain bearing a deleted promoter region lacking sequences upstream from position -570. Such a strain was still able to differentiate functional heterocysts and to grow diazotrophically, although diazotrophic growth was impaired under certain conditions. Similarly, a second, NtcA-dependent, HetR-dependent transcriptional start site was identified at position -454 in the promoter region upstream from the devBCA operon encoding an ABC transport system involved in heterocyst maturation, in which an NtcA-dependent promoter producing transcripts starting at position -704 had been previously noted. Thus, the hetC and devBCA promoter regions exhibit similar tandem promoter arrangements. |
Agencias financiadoras | Ministerio de Educación y Ciencia (MEC). España |
Cita | Muro Pastor, M.I., Flores García, E. y Herrero, A. (2009). NtcA-regulated heterocyst differentiation genes hetC and devB from Anabaena sp. strain PCC 7120 exhibit a similar tandem promoter arrangement. Journal of Bacteriology, 191 (18), 5765-5774. |
Ficheros | Tamaño | Formato | Ver | Descripción |
---|---|---|---|---|
NtcA-Regulated Heterocyst.pdf | 1.397Mb | [PDF] | Ver/ | |