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Organization and expression of photosynthesis genes and operons in anoxygenic photosynthetic proteobacteria
Author(s) -
Liotenberg Sylviane,
Steunou AnneSoisig,
Picaud Martine,
ReissHusson Françoise,
Astier Chantal,
Ouchane Soufian
Publication year - 2008
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1111/j.1462-2920.2008.01649.x
Subject(s) - anoxygenic photosynthesis , biology , operon , gene cluster , gene , gammaproteobacteria , genetics , betaproteobacteria , proteobacteria , genome , phototroph , actinobacteria , bacteria , escherichia coli , 16s ribosomal rna
Summary Genes belonging to the same metabolic route are usually organized in operons in microbial genomes. For instance, most genes involved in photosynthesis were found clustered and organized in operons in photosynthetic Alpha ‐ and Betaproteobacteria . The discovery of Gammaproteobacteria with a conserved photosynthetic gene cluster revives the questions on the role and the maintenance of such organization in proteobacteria. In this paper, we report the analysis of the structure and expression of the 14 kb cluster ( crtEF‐bchCXYZ‐pufBALMC‐crtADC ) in the photosynthetic betaproteobacterium Rubrivivax gelatinosus , with the purpose of understanding the reasons and the biological constraints that might have led to the clustering of photosynthesis genes. The genetic analyses are substantiated by reverse transcription‐PCR data which reveal the presence of a transcript encompassing the 14 genes and provide evidence of a polycistronic ‘super‐operon’ organization starting at crtE and ending 14 kb downstream at the crtC gene. Furthermore, genetic analyses suggest that one of the selection pressures that may have driven and maintained the photosynthesis operons/super‐operons in proteobacteria could very likely be the coexpression and regulation of the clustered genes/operon.