title: Robust translation of the nucleoid protein Fis requires a remote upstream AU element and is enhanced by RNA secondary structure.
abstract: Synthesis of the Fis nucleoid protein rapidly increases in response to nutrient upshifts, and Fis is one of the most abundant DNA binding proteins in Escherichia coli under nutrient-rich growth conditions. Previous work has shown that control of Fis synthesis occurs at transcription initiation of the dusB-fis operon. We show here that while translation of the dihydrouridine synthase gene dusB is low, unusual mechanisms operate to enable robust translation of fis. At least two RNA sequence elements located within the dusB coding region are responsible for high fis translation. The most important is an AU element centered 35 nucleotides (nt) upstream of the fis AUG, which may function as a binding site for ribosomal protein S1. In addition, a 44-nt segment located upstream of the AU element and predicted to form a stem-loop secondary structure plays a prominent role in enhancing fis translation. On the other hand, mutations close to the AUG, including over a potential Shine-Dalgarno sequence, have little effect on Fis protein levels. The AU element and stem-loop regions are phylogenetically conserved within dusB-fis operons of representative enteric bacteria.
authors.affiliation: Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA.
authors.forename: Maryam
authors.initials: M
authors.lastname: Nafissi
authors.forename: Jeannette
authors.initials: J
authors.lastname: Chau
authors.forename: Jimin
authors.initials: J
authors.lastname: Xu
authors.forename: Reid C
authors.initials: RC
authors.lastname: Johnson
mesh_terms: D001483:Base Sequence; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D035021:Factor For Inversion Stimulation Protein / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology*; D009154:Mutation; D009690:Nucleic Acid Conformation; D009876:Operon; D011485:Protein Binding; D014176:Protein Biosynthesis; D012329:RNA, Bacterial / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D029968:Escherichia coli Proteins; D035021:Factor For Inversion Stimulation Protein; C501034:Fis protein, E coli; D012329:RNA, Bacterial; D012333:RNA, Messenger