Role of two NtcA-binding sites in the complex ntcA gene promoter of the heterocyst-forming cyanobacterium Anabaena sp. strain PCC 7120.

ABSTRACT: Anabaena sp. strain PCC 7120 is a filamentous cyanobacterium that fixes N(2) in specialized cells called heterocysts, which differentiate from vegetative cells in a process that requires the nitrogen control transcription factor NtcA. 2-Oxoglutarate-stimulated binding of purified NtcA to wild-type and modified versions of the ntcA gene promoter from Anabaena sp. was analyzed by mobility shift and DNase I footprinting assays, and the role of NtcA-binding sites in the expression of the ntcA gene during heterocyst differentiation was studied in vivo by using an ntcA-gfp translational fusion and primer extension analysis. Mutation of neither of the two identified NtcA-binding sites eliminated localized expression of ntcA in proheterocysts, but mutation of both sites led to very low, nonlocaliz

SUBMITTER: Olmedo-Verd E 

PROVIDER: S-EPMC2576654 | biostudies-literature | 2008 Nov

REPOSITORIES: biostudies-literature