title: The cbbQ genes, located downstream of the form I and form II RubisCO genes, affect the activity of both RubisCOs.
abstract: Hydrogenovibrio marinus strain MH-110, an obligately lithoautotrophic hydrogen-oxidizing bacterium, possesses three sets of the genes for ribulose 1,5-bisphosphate carboxylase/oxygenase (RubisCO): namely, two form I type (cbbLS-1 and cbbLS-2) and one form II type (cbbM) enzymes. The cbbQ-m gene was located downstream of cbbM, and showed high similarity to other cbbQ genes and nirQ/norQ genes in denitrifying bacteria. Phylogenetic analysis of CbbQ and NirQ/NorQ indicated that CbbQ-m from Hv. marinus closely resembled CbbQ from Thiobacillus intermedius and Thiobacillus neapolitannus and less closely resembled NirQ and NorQ. The cbbQ-m gene has been shown to activate the form II RubisCO in E. coli cells, and the cbbQ-t from Hydrogenophilus thermoluteolus could also activate the form II RubisCO. Both cbbQ genes have also been shown to activate the form I RubisCO from Hp. thermoluteolus in E. coli cells. However, the activation levels of two form I RubisCOs from Hv. marinus were smaller than that of form I RubisCOs from Hp. thermoluteolus. Form II RubisCO activated by CbbQ-m (QM) was purified from E. coli cells. The result of the 8-anilino-1-naphthalenesulfonate binding assay and the circular dichroism spectra indicated that QM was conformationally different from Form II RubisCO that was not activated by CbbQ.
authors.affiliation: Department of Biotechnology, University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo, 113-8657, Japan.
authors.forename: N R
authors.initials: NR
authors.lastname: Hayashi
authors.forename: H
authors.initials: H
authors.lastname: Arai
authors.forename: T
authors.initials: T
authors.lastname: Kodama
authors.forename: Y
authors.initials: Y
authors.lastname: Igarashi
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D003001:Cloning, Molecular; D004926:Escherichia coli; D019143:Evolution, Molecular; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D011487:Protein Conformation; D015183:Restriction Mapping; D012273:Ribulose-Bisphosphate Carboxylase / Q000235:genetics* / Q000378:metabolism*; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013855:Thiobacillus / Q000201:enzymology / Q000235:genetics; D014737:Vibrionaceae / Q000201:enzymology / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; C092405:CbbQ protein, bacteria; D007527:Isoenzymes; D012273:Ribulose-Bisphosphate Carboxylase