Distribution and Origin of Oxygen-Dependent and Oxygen-Independent Forms of Mg-Protoporphyrin Monomethylester Cyclase among Phototrophic Proteobacteria

0422207 - MBÚ 2014 RIV US eng J - Journal Article
Boldareva, Ekaterina - Bláhová, Zuzana - Sobotka, Roman - Koblížek, Michal
Distribution and Origin of Oxygen-Dependent and Oxygen-Independent Forms of Mg-Protoporphyrin Monomethylester Cyclase among Phototrophic Proteobacteria.
Applied and Environmental Microbiology. Roč. 79, č. 8 (2013), s. 2596-2604. ISSN 0099-2240. E-ISSN 1098-5336
R&D Projects: GA ČR GAP501/10/0221; GA ČR GBP501/12/G055; GA MŠMT(CZ) ED2.1.00/03.0110
Institutional support: RVO:61388971
Keywords : AEROBIC ANOXYGENIC PHOTOTROPHS * CHLOROPHYLL ISOCYCLIC RING * PURPLE BACTERIA
Subject RIV: EE - Microbiology, Virology
Impact factor: 3.952, year: 2013

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
Permanent Link: http://hdl.handle.net/11104/0228387