Open AccessHeterogeneous rRNAs are differentially expressed during the morphological development of Streptomyces coelicolor
Author(s) -
Kim HyunLee,
Shin EunKyoung,
Kim HongMan,
Ryou SangMi,
Kim Sanggoo,
Cha ChangJun,
Bae Jeehyeon,
Lee Kangseok
Publication year - 2007
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2007.00872.x
Subject(s) - ribosomal rna , streptomyces coelicolor , biology , operon , internal transcribed spacer , ribosome , gene , genetics , 23s ribosomal rna , rna , escherichia coli , mutant
It is generally assumed that all mature rRNA molecules assembled into ribosomes within a single cell are identical. However, sequence analysis of Streptomyces coelicolor genome revealed that it harbors six copies of divergent rRNA operons that may express and constitute three and five different kinds of small subunit (SSU) and large subunit (LSU) rRNA molecules, respectively, in a single cell. Phylogenetic analyses of the LSU rRNA genes and the internal transcribed spacer between SSU and LSU genes indicated that the LSU gene of rrn A and rrn E operons might be the result of interspecies recombination between rRNA genes in closely related streptomycetes. Profiling of rRNA species using primer extension analysis showed that heterogeneous rRNA transcripts are expressed and assembled into ribosomes in the cell. As the cells developed from germination to sporulation, the relative amount of LSU rRNA molecules derived from three rRNA operons ( rrn A, D, and E) gradually decreased from ∼85% to ∼60%, whereas the distribution of LSU rRNA molecules from two other operons ( rrn B and F) and rrn C operon gradually increased from ∼10% to ∼20% of the total LSU rRNA. These findings indicate that heterogeneous rRNA molecules are differentially expressed during the life cycle of this developmentally complex microorganism.