Characterization of two chloroplast RNA polymerase sigma factors from Zea mays: photoregulation and differential expression.

ABSTRACT: Two distinct cDNAs encoding putative sigma factors of plastid RNA polymerase were isolated from Zea mays, a C4 plant. The deduced amino acid sequences of both cDNAs possess all four highly conserved domains proposed for recognition of -10 and -35 promoter elements, core complex binding, DNA binding, and melting. These two cDNAs are designated sig1 and sig2. Phylogenetic analysis of available plastid sigma factors indicated that they were probably the descendants of cyanobacterial principal sigma factors. Southern blots probed with sig1 and sig2 revealed that both genes exist in the maize nuclear genome as single-copy genes, but low-stringency hybridization suggested the presence of a multigene family of maize plastid sigma factors. Transcription of sig1 and sig2 is light inducible and tiss

SUBMITTER: Tan S 

PROVIDER: S-EPMC21861 | biostudies-literature | 1999 Apr

REPOSITORIES: biostudies-literature