title: A helicase gene (helO) in Rhizobium meliloti WSM419.
abstract: A 2.8 kb BamHI DNA fragment adjacent to a BamHI fragment containing actR-actS (a sensor/regulator pair required for low pH tolerance in Rhizobium meliloti WSM419) was cloned and sequenced. A computer predicted protein of 821 amino acids, designated HelO, showed extensive similarity with 'DEAH' motif helicases. Expression of helO was higher at pH 7.0 than pH 5.8 and it did not require the product of the actR gene. Inactivation of helO by insertion of a omega interposon at codon 40 did not affect nodulation, growth or tolerance to low pH, high temperature, osmolarity or elevated levels of copper or zinc.
authors.affiliation: Nitrogen Fixation Research Group, School of Biological and Environmental Sciences, Murdoch University, Australia.
authors.forename: W G
authors.initials: WG
authors.lastname: Reeve
authors.forename: R P
authors.initials: RP
authors.lastname: Tiwari
authors.forename: M J
authors.initials: MJ
authors.lastname: Dilworth
authors.forename: A R
authors.initials: AR
authors.lastname: Glenn
mesh_terms: D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D004265:DNA Helicases / Q000235:genetics*; D018628:Gene Dosage; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D005798:Genes, Bacterial / Q000235:genetics*; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D015183:Restriction Mapping; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D016962:Sinorhizobium meliloti / Q000201:enzymology / Q000235:genetics*
chemical_list: D004265:DNA Helicases