title: Molecular cloning of the gene encoding RNA polymerase alpha subunit from deep-sea barophilic bacterium.
abstract: We have cloned the gene encoding RNA polymerase alpha subunit from a gene library of deep-sea barophilic bacterium strain DB6705. The clone contains the genes for ribosomal protein S4, RNA polymerase subunit alpha and ribosomal protein L17 in this order. The alpha gene has 328 amino acids and a molecular mass of 36 100 Da with 86.9% identity to Escherichia coli alpha gene. Differences between the two sequences were mainly in the N-terminal portion of the alpha subunit, which is involved in the assembly of the core RNA polymerase; while the 87 C-terminal residues, which form a region involved in contact with some positive regulators and rrnB P1 promoter region called UP-element, were identical in the both strain. Plasmid encoding the alpha subunit with an N-terminal hexahistidine tag was constructed. Using the plasmid, the recombinant fusion alpha subunit was overexpressed and successfully purified to near homogeneity.
authors.affiliation: DEEP STAR group, Japan Marine Science and Technology Center, Kanagawa, Japan. nakasone@mstunx.jamstec.go.jp
authors.forename: K
authors.initials: K
authors.lastname: Nakasone
authors.forename: C
authors.initials: C
authors.lastname: Kato
authors.forename: K
authors.initials: K
authors.lastname: Horikoshi
mesh_terms: D000595:Amino Acid Sequence; D001419:Bacteria / Q000201:enzymology / Q000235:genetics*; D001483:Base Sequence; D003001:Cloning, Molecular; D012321:DNA-Directed RNA Polymerases / Q000096:biosynthesis / Q000235:genetics*; D005798:Genes, Bacterial; D006639:Histidine / Q000235:genetics; D006874:Hydrostatic Pressure; D008386:Marine Biology; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D015183:Restriction Mapping; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014871:Water Microbiology
chemical_list: D011993:Recombinant Fusion Proteins; D006639:Histidine; D012321:DNA-Directed RNA Polymerases