The Conserved Dcw Gene Cluster of R. sphaeroides Is Preceded by an Uncommonly Extended 5' Leader Featuring the sRNA UpsM.
Cell division and cell wall synthesis mechanisms are similarly conserved among bacteria. Consequently some bacterial species have comparable sets of genes organized in the dcw (division and cell wall) gene cluster. Dcw genes, their regulation and their relative order within the cluster are outstandingly conserved among rod shaped and gram negative bacteria to ensure an efficient coordination of growth and division. A well studied representative is the dcw gene cluster of E. coli. The first promoter of the gene cluster (mraZ1p) gives rise to polycistronic transcripts containing a 38 nt long 5' UTR followed by the first gene mraZ. Despite reported conservation we present evidence for a much longer 5' UTR in the gram negative and rod shaped bacterium Rhodobacter sphaeroides and in the family of Rhodobacteraceae. This extended 268 nt long 5' UTR comprises a Rho independent terminator, which in case of termination gives rise to a non-coding RNA (UpsM). This sRNA is conditionally cleaved by RNase E under stress conditions in an Hfq- and very likely target mRNA-dependent manner, implying its function in trans. These results raise the question for the regulatory function of this extended 5' UTR. It might represent the rarely described case of a trans acting sRNA derived from a riboswitch with exclusive presence in the family of Rhodobacteraceae.
Institute of Microbiology and Molecular Biology, IFZ, Justus-Liebig-University Giessen, Giessen, Germany.
Lennart
L
Weber
Institute of Pharmaceutical Chemistry, Philipps-University Marburg, Marburg, Germany.
Clemens
C
Thoelken
Institute of Microbiology and Molecular Biology, IFZ, Justus-Liebig-University Giessen, Giessen, Germany.
Marcel
M
Volk
Institute of Microbiology and Molecular Biology, IFZ, Justus-Liebig-University Giessen, Giessen, Germany.
Bernhard
B
Remes
Institute of Pharmaceutical Chemistry, Philipps-University Marburg, Marburg, Germany.
Marcus
M
Lechner
Institute of Microbiology and Molecular Biology, IFZ, Justus-Liebig-University Giessen, Giessen, Germany.
Gabriele
G
Klug
D020121:5' Untranslated Regions; D004926:Escherichia coli / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D005810:Multigene Family; D012329:RNA, Bacterial / Q000235:genetics; D022661:RNA, Untranslated / Q000235:genetics; D012242:Rhodobacter sphaeroides / Q000235:genetics*
D020121:5' Untranslated Regions; D012329:RNA, Bacterial; D022661:RNA, Untranslated