title: Distribution and origin of oxygen-dependent and oxygen-independent forms of Mg-protoporphyrin monomethylester cyclase among phototrophic proteobacteria.
abstract: Magnesium-protoporphyrin IX monomethylester cyclase is one of the key enzymes of the bacteriochlorophyll biosynthesis pathway. There exist two fundamentally different forms of this enzyme. The oxygen-dependent form, encoded by the gene acsF, catalyzes the formation of the bacteriochlorophyll fifth ring using oxygen, whereas the oxygen-independent form encoded by the gene bchE utilizes an oxygen atom extracted from water. The presence of acsF and bchE genes was surveyed in various phototrophic Proteobacteria using the available genomic data and newly designed degenerated primers. It was found that while the majority of purple nonsulfur bacteria contained both forms of the cyclase, the purple sulfur bacteria contained only the oxygen-independent form. All tested species of aerobic anoxygenic phototrophs contained acsF genes, but some of them also retained the bchE gene. In contrast to bchE phylogeny, the acsF phylogeny was in good agreement with 16S inferred phylogeny. Moreover, the survey of the genome data documented that the acsF gene occupies a conserved position inside the photosynthesis gene cluster, whereas the bchE location in the genome varied largely between the species. This suggests that the oxygen-dependent cyclase was recruited by purple phototrophic bacteria very early during their evolution. The primary sequence and immunochemical similarity with its cyanobacterial counterparts suggests that acsF may have been acquired by Proteobacteria via horizontal gene transfer from cyanobacteria. The acquisition of the gene allowed purple nonsulfur phototrophic bacteria to proliferate in the mildly oxygenated conditions of the Proterozoic era.
authors: Institute of Microbiology CAS, Department of Phototrophic Microorganisms, Algatech, Opatovický mlýn, Třeboň, Czech Republic.
authors: Ekaterina N
authors: EN
authors: Boldareva-Nuianzina
authors: Zuzana
authors: Z
authors: Bláhová
authors: Roman
authors: R
authors: Sobotka
authors: Michal
authors: M
authors: Koblízek
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis / Q000737:chemistry / Q000235:genetics*; D000458:Cyanobacteria / Q000201:enzymology / Q000235:genetics; D016680:Genome, Bacterial; D010100:Oxygen / Q000378:metabolism; D010105:Oxygenases / Q000032:analysis* / Q000737:chemistry / Q000235:genetics*; D010788:Photosynthesis / Q000235:genetics; D010802:Phylogeny; D020033:Protein Isoforms / Q000032:analysis / Q000737:chemistry / Q000235:genetics; D020560:Proteobacteria / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D020033:Protein Isoforms; D010105:Oxygenases; C053161:magnesium protoporphyrin monomethyl ester oxidative cyclase; D010100:Oxygen
references: Plant Physiol. 2010 Oct;154(2):434-8
references: 20921158
references: Arch Microbiol. 2003 Nov;180(5):327-38
references: 14504692
references: Appl Environ Microbiol. 2005 Jan;71(1):344-53
references: 15640208
references: Arch Microbiol. 2010 Jan;192(1):41-9
references: 19949940
references: FEMS Microbiol Ecol. 2011 May;76(2):393-400
references: 21265869
references: Philos Trans R Soc Lond B Biol Sci. 2006 Jun 29;361(1470):903-15
references: 16754606
references: Biochem J. 1989 Jan 15;257(2):599-602
references: 2930469
references: Science. 2001 Jun 29;292(5526):2492-5
references: 11431568
references: Biochim Biophys Acta. 2009 Dec;1787(12):1458-67
references: 19540827
references: Environ Microbiol. 2007 Jun;9(6):1464-75
references: 17504484
references: Plant Physiol. 1996 Sep;112(1):105-114
references: 12226378
references: J Bacteriol. 2002 Feb;184(3):746-53
references: 11790744
references: Plant Physiol. 1982 Oct;70(4):987-93
references: 16662656
references: J Bacteriol. 2009 Jun;191(11):3580-7
references: 19346304
references: Appl Environ Microbiol. 2007 Jun;73(12):3936-44
references: 17468276
references: Science. 2000 Sep 8;289(5485):1703-5
references: 11001737
references: Appl Environ Microbiol. 2012 Oct;78(20):7414-9
references: 22885759
references: PLoS One. 2011;6(9):e25050
references: 21949847
references: Environ Microbiol. 2008 Aug;10(8):1988-96
references: 18430010
references: Lipids. 2005 Jan;40(1):97-108
references: 15825835
references: J Biol Chem. 2008 Feb 1;283(5):2684-92
references: 18039649
references: Philos Trans R Soc Lond B Biol Sci. 2008 Aug 27;363(1504):2731-43
references: 18468984
references: Plant Cell. 2002 Mar;14(3):673-88
references: 11910013
references: Annu Rev Microbiol. 2007;61:113-29
references: 17506685
references: Mikrobiologiia. 2008 Mar-Apr;77(2):241-54
references: 18522327
references: Proc Natl Acad Sci U S A. 2003 Dec 23;100(26):16119-24
references: 14673103
references: J Biol Chem. 2004 Feb 20;279(8):6385-94
references: 14617630
references: Proc Natl Acad Sci U S A. 2000 Jun 6;97(12):6908-13
references: 10841582
references: Environ Microbiol. 2007 Dec;9(12):3091-9
references: 17991036
references: BMC Evol Biol. 2004 Nov 09;4:44
references: 15535883
references: Mikrobiologiia. 2007 Jan-Feb;76(1):95-106
references: 17410880
references: Proc Natl Acad Sci U S A. 2009 Oct 6;106(40):16925-9
references: 19805080