Localization and mapping of CO2 fixation genes within two gene clusters in Rhodobacter sphaeroides.
Two fructose 1,6-bisphosphatase structural genes (fbpA and fbpB) have been identified within two unlinked gene clusters that were previously shown to contain the Rhodobacter sphaeroides sequences that code for form I and form II ribulose 1,5-bisphosphate carboxylase-oxygenase and phosphoribulokinase. The fbpA and fbpB genes were localized to a region immediately upstream from the corresponding prkA and prkB sequences and were found to be transcribed in the same direction as the phosphoribulokinase and ribulose 1,5-bisphosphate carboxylase-oxygenase genes based on inducible expression of fructose 1,6-bisphosphatase activity directed by the lac promoter. A recombinant plasmid was constructed that contained the tandem fbpA and prkA genes inserted downstream from the lac promoter in plasmid pUC18. Both gene products were expressed in Escherichia coli upon induction of transcription with isopropyl beta-D-thiogalactoside, demonstrating that the two genes can be cotranscribed. A Zymomonas mobilis glyceraldehyde 3-phosphate-dehydrogenase gene (gap) hybridized to a DNA sequence located approximately 1 kilobase upstream from the form II ribulose 1,5-bisphosphate carboxylase-oxygenase gene. Although no corresponding gap sequence was found within the form I gene cluster, an additional region of homology was detected immediately upstream from the sequences that encode the form I and form II ribulose 1,5-bisphosphate carboxylase-oxygenases.
Gibson
J L
JL
Center for Applied Microbiology, University of Texas, Austin 78712-1095.
Tabita
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D002245:Carbon Dioxide / Q000378:metabolism*; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000235:genetics; D006597:Fructose-Bisphosphatase / Q000235:genetics*; D005786:Gene Expression Regulation; D005796:Genes; D005798:Genes, Bacterial; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000235:genetics; D009693:Nucleic Acid Hybridization; D010770:Phosphotransferases / Q000235:genetics*; D017853:Phosphotransferases (Alcohol Group Acceptor); D012242:Rhodobacter sphaeroides / Q000201:enzymology / Q000235:genetics*; D012273:Ribulose-Bisphosphate Carboxylase / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic
D004269:DNA, Bacterial; D002245:Carbon Dioxide; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D010770:Phosphotransferases; D017853:Phosphotransferases (Alcohol Group Acceptor); C022390:phosphoribulokinase; D006597:Fructose-Bisphosphatase; D012273:Ribulose-Bisphosphate Carboxylase