title: 5'-coding sequence of the nasA gene of Azotobacter vinelandii is required for efficient expression.
abstract: The operon nasACBH in Azotobacter vinelandii encodes nitrate and nitrite reductases that sequentially reduce nitrate to nitrite and to ammonium for nitrogen assimilation into organic molecules. Our previous analyses showed that nasACBH expression is subject to antitermination regulation that occurs upstream of the nasA gene in response to the availability of nitrate and nitrite. In this study, we continued expression analyses of the nasA gene and observed that the nasA 5'-coding sequence plays an important role in gene expression, as demonstrated by the fact that deletions caused over sixfold reduction in the expression of the lacZ reporter gene. Further analysis suggests that the nasA 5'-coding sequence promotes gene expression in a way that is not associated with weakened transcript folding around the translational initiation region or codon usage bias. The findings from this study imply that there exists potential to improve gene expression in A. vinelandii by optimizing 5'-coding sequences.
authors.affiliation: The School of Plant Sciences, University of Arizona, Tucson, AZ, USA; Department of Medicine, Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, VA, USA.
authors.forename: Baomin
authors.initials: B
authors.lastname: Wang
authors.forename: Yumei
authors.initials: Y
authors.lastname: Wang
authors.forename: Christina
authors.initials: C
authors.lastname: Kennedy
mesh_terms: D016948:Azotobacter vinelandii / Q000201:enzymology / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics; D001483:Base Sequence; D003062:Codon; D004252:DNA Mutational Analysis; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D050901:Nitrate Reductase / Q000378:metabolism; D009572:Nitrite Reductases / Q000235:genetics* / Q000378:metabolism; D009690:Nucleic Acid Conformation; D009876:Operon / Q000235:genetics; D012329:RNA, Bacterial / Q000737:chemistry / Q000235:genetics; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D003062:Codon; D012329:RNA, Bacterial; D012333:RNA, Messenger; D009572:Nitrite Reductases; D050901:Nitrate Reductase
keywords: Pseudomonas; adenine-rich sequence; mRNA folding; nitrite reductase; translation