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J Bacteriol. Feb 1994; 176(3): 886–895.
PMCID: PMC205126

Azorhizobium caulinodans respires with at least four terminal oxidases.

Abstract

In culture, Azorhizobium caulinodans used at least four terminal oxidases, cytochrome aa3 (cytaa3), cytd, cyto, and a second a-type cytochrome, which together mediated general, respiratory electron (e-) transport to O2. To genetically dissect physiological roles for these various terminal oxidases, corresponding Azorhizobium apocytochrome genes were cloned, and three cytaa3 mutants, a cytd mutant, and a cytaa3, cytd double mutant were constructed by reverse genetics. These cytochrome oxidase mutants were tested for growth, oxidase activities, and N2 fixation properties both in culture and in symbiosis with the host plant Sesbania rostrata. The cytaa3 mutants grew normally, fixed N2 normally, and remained fully able to oxidize general respiratory e- donors (NADH, succinate) which utilize a cytc-dependent oxidase. By difference spectroscopy, a second, a-type cytochrome was detected in the cytaa3 mutants. This alternative a-type cytochrome (Amax = 610 nm) was also present in the wild type but was masked by bona fide cytaa3 (Amax = 605 nm). In late exponential-phase cultures, the cytaa3 mutants induced a new, membrane-bound, CO-binding cytc550, which also might serve as a cytc oxidase (a fifth terminal oxidase). The cloned Azorhizobium cytaa3 genes were strongly expressed during exponential growth but were deactivated prior to onset of stationary phase. Azorhizobium cytd mutants showed 40% lower N2 fixation rates in culture and in planta, but aerobic growth rates were wild type. The cytaa3, cytd double mutant showed 70% lower N2 fixation rates in planta. Pleiotropic cytc mutants were isolated by screening for strains unable to use N,N,N',N'-tetramethyl-p-phenylenediamine as a respiratory e- donor. These mutants synthesized no detectable cytc, excreted coproporphyrin, grew normally in aerobic minimal medium, grew poorly in rich medium, and fixed N2 poorly both in culture and in planta. Therefore, while aerobic growth was sustained by quinol oxidases alone, N2 fixation required cytc oxidase activities. Assuming that the terminal oxidases function as do their homologs in other bacteria, Azorhizobium respiration simultaneously employs both quinol and cytc oxidases. Because Azorhizobium terminal oxidase mutants were able to reformulate their terminal oxidase mix and grow more or less normally in aerobic culture, these terminal oxidases are somewhat degenerate. Its extensive terminal oxidase repertoire might allow Azorhizobium spp. to flourish in wide-ranging O2 environments.

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Selected References

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  • Anraku Y. Bacterial electron transport chains. Annu Rev Biochem. 1988;57:101–132. [PubMed]
  • Appleby CA. Electron transport systems of Rhizobium japonicum. I. Haemoprotein P-450, other CO-reactive pigments, cytochromes and oxidases in bacteroids from N2-fixing root nodules. Biochim Biophys Acta. 1969 Jan 14;172(1):71–87. [PubMed]
  • Biel SW, Biel AJ. Isolation of a Rhodobacter capsulatus mutant that lacks c-type cytochromes and excretes porphyrins. J Bacteriol. 1990 Mar;172(3):1321–1326. [PMC free article] [PubMed]
  • Bott M, Bolliger M, Hennecke H. Genetic analysis of the cytochrome c-aa3 branch of the Bradyrhizobium japonicum respiratory chain. Mol Microbiol. 1990 Dec;4(12):2147–2157. [PubMed]
  • Bott M, Preisig O, Hennecke H. Genes for a second terminal oxidase in Bradyrhizobium japonicum. Arch Microbiol. 1992;158(5):335–343. [PubMed]
  • Buckmiller LM, Lapointe JP, Ludwig RA. Cloning of Azorhizobium caulinodans nicotinate catabolism genes and characterization of their importance in N2 fixation. J Bacteriol. 1991 Mar;173(6):2017–2025. [PMC free article] [PubMed]
  • Chepuri V, Lemieux L, Au DC, Gennis RB. The sequence of the cyo operon indicates substantial structural similarities between the cytochrome o ubiquinol oxidase of Escherichia coli and the aa3-type family of cytochrome c oxidases. J Biol Chem. 1990 Jul 5;265(19):11185–11192. [PubMed]
  • de Vries W, Stam H, Stouthamer AH. Hydrogen oxidation and nitrogen fixation in rhizobia, with special attention focused on strain ORS 571. Antonie Van Leeuwenhoek. 1984;50(5-6):505–524. [PubMed]
  • Donald RG, Ludwig RA. Rhizobium sp. strain ORS571 ammonium assimilation and nitrogen fixation. J Bacteriol. 1984 Jun;158(3):1144–1151. [PMC free article] [PubMed]
  • Donald RG, Raymond CK, Ludwig RA. Vector insertion mutagenesis of Rhizobium sp. strain ORS571: direct cloning of mutagenized DNA sequences. J Bacteriol. 1985 Apr;162(1):317–323. [PMC free article] [PubMed]
  • Ogg SC, Anderson P, Wickens MP. Splicing of a C. elegans myosin pre-mRNA in a human nuclear extract. Nucleic Acids Res. 1990 Jan 11;18(1):143–149. [PMC free article] [PubMed]
  • Green GN, Fang H, Lin RJ, Newton G, Mather M, Georgiou CD, Gennis RB. The nucleotide sequence of the cyd locus encoding the two subunits of the cytochrome d terminal oxidase complex of Escherichia coli. J Biol Chem. 1988 Sep 15;263(26):13138–13143. [PubMed]
  • Hill S, Viollet S, Smith AT, Anthony C. Roles for enteric d-type cytochrome oxidase in N2 fixation and microaerobiosis. J Bacteriol. 1990 Apr;172(4):2071–2078. [PMC free article] [PubMed]
  • Jones CW, Redfearn ER. Electron transport in Azotobacter vinelandii. Biochim Biophys Acta. 1966 Mar 7;113(3):467–481. [PubMed]
  • Kelly MJ, Poole RK, Yates MG, Kennedy C. Cloning and mutagenesis of genes encoding the cytochrome bd terminal oxidase complex in Azotobacter vinelandii: mutants deficient in the cytochrome d complex are unable to fix nitrogen in air. J Bacteriol. 1990 Oct;172(10):6010–6019. [PMC free article] [PubMed]
  • Kitts CL, Lapointe JP, Lam VT, Ludwig RA. Elucidation of the complete Azorhizobium nicotinate catabolism pathway. J Bacteriol. 1992 Dec;174(23):7791–7797. [PMC free article] [PubMed]
  • Kitts CL, Schaechter LE, Rabin RS, Ludwig RA. Identification of cyclic intermediates in Azorhizobium caulinodans nicotinate catabolism. J Bacteriol. 1989 Jun;171(6):3406–3411. [PMC free article] [PubMed]
  • Moshiri F, Chawla A, Maier RJ. Cloning, characterization, and expression in Escherichia coli of the genes encoding the cytochrome d oxidase complex from Azotobacter vinelandii. J Bacteriol. 1991 Oct;173(19):6230–6241. [PMC free article] [PubMed]
  • Nautiyal CS, van Berkum P, Sadowsky MJ, Keister DL. Cytochrome mutants of bradyrhizobium induced by transposon tn5. Plant Physiol. 1989 Jun;90(2):553–559. [PMC free article] [PubMed]
  • Noel KD, Sanchez A, Fernandez L, Leemans J, Cevallos MA. Rhizobium phaseoli symbiotic mutants with transposon Tn5 insertions. J Bacteriol. 1984 Apr;158(1):148–155. [PMC free article] [PubMed]
  • O'Brian MR, Kirshbom PM, Maier RJ. Tn5-induced cytochrome mutants of Bradyrhizobium japonicum: effects of the mutations on cells grown symbiotically and in culture. J Bacteriol. 1987 Mar;169(3):1089–1094. [PMC free article] [PubMed]
  • O'brian MR, Maier RJ. Isolation of a cytochrome aa(3) gene from Bradyrhizobium japonicum. Proc Natl Acad Sci U S A. 1987 May;84(10):3219–3223. [PMC free article] [PubMed]
  • Poole RK. Bacterial cytochrome oxidases. A structurally and functionally diverse group of electron-transfer proteins. Biochim Biophys Acta. 1983 Sep 15;726(3):205–243. [PubMed]
  • Preisig O, Anthamatten D, Hennecke H. Genes for a microaerobically induced oxidase complex in Bradyrhizobium japonicum are essential for a nitrogen-fixing endosymbiosis. Proc Natl Acad Sci U S A. 1993 Apr 15;90(8):3309–3313. [PMC free article] [PubMed]
  • Raitio M, Jalli T, Saraste M. Isolation and analysis of the genes for cytochrome c oxidase in Paracoccus denitrificans. EMBO J. 1987 Sep;6(9):2825–2833. [PMC free article] [PubMed]
  • Rossbach S, Loferer H, Acuña G, Appleby CA, Hennecke H. Cloning, sequencing and mutational analysis of the cytochrome c552 gene (cycB) from Bradyrhizobium japonicum strain 110. FEMS Microbiol Lett. 1991 Oct 1;67(2):145–152. [PubMed]
  • Sharma SB, Signer ER. Temporal and spatial regulation of the symbiotic genes of Rhizobium meliloti in planta revealed by transposon Tn5-gusA. Genes Dev. 1990 Mar;4(3):344–356. [PubMed]
  • Smith A, Hill S, Anthony C. The purification, characterization and role of the d-type cytochrome oxidase of Klebsiella pneumoniae during nitrogen fixation. J Gen Microbiol. 1990 Jan;136(1):171–180. [PubMed]
  • Soberón M, Williams HD, Poole RK, Escamilla E. Isolation of a Rhizobium phaseoli cytochrome mutant with enhanced respiration and symbiotic nitrogen fixation. J Bacteriol. 1989 Jan;171(1):465–472. [PMC free article] [PubMed]
  • Thöny-Meyer L, Stax D, Hennecke H. An unusual gene cluster for the cytochrome bc1 complex in Bradyrhizobium japonicum and its requirement for effective root nodule symbiosis. Cell. 1989 May 19;57(4):683–697. [PubMed]
  • Tully RE, Sadowsky MJ, Keister DL. Characterization of cytochromes c550 and c555 from Bradyrhizobium japonicum: cloning, mutagenesis, and sequencing of the c555 gene (cycC). J Bacteriol. 1991 Dec;173(24):7887–7895. [PMC free article] [PubMed]
  • Yang T. Biochemical and biophysical properties of cytochrome o of Azotobacter vinelandii. Biochim Biophys Acta. 1986 Mar 12;848(3):342–351. [PubMed]

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