Structural and functional analysis of the gene cluster encoding carotenoid biosynthesis in Mycobacterium aurum A+

Viveiros, Miguel

doi:10.1016/s0378-1097(00)00182-8

Cited by 23 publications

(45 citation statements)

References 22 publications

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“…Assuming that M. marinum has about the same number of genes as M. tuberculosis (ϳ4,000), if transposition is random, the Poisson statistic predicts that the likelihood of failure to find in this library at least one insertion in any gene involved in pigmentation is approximately 2%. Normally, M. marinum is gold when exposed to light because of the production of carotenoid pigments (30,45). We identified eight colonies that demonstrated pigmentation variations: four of them lost pigment, resulting in white colonies (MmW01 to MmW04); three others showed a red colony color upon exposure to light (MmR01, MmR02, and MmR04); and one appeared red in the dark and developed a gold color after exposure to light (MmR03) (Fig.…”

Section: Resultsmentioning

confidence: 96%

Transposon Mutagenesis ofMycobacterium marinumIdentifies a Locus Linking Pigmentation and Intracellular Survival

Gao¹,

Groger²,

Cox

et al. 2003

Infect Immun

106

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Pathogenic mycobacteria survive and replicate within host macrophages, but the molecular mechanisms involved in this necessary step in the pathogenesis of infection are not completely understood. Mycobacterium marinum has recently been used as a model for aspects of the pathogenesis of tuberculosis because of its close genetic relationship to Mycobacterium tuberculosis and because of similarities in the pathology and course of infection caused by this organism in its natural hosts, fish and frogs, with tuberculosis in humans. In order to advance the utility of the M. marinum model, we have developed efficient transposon mutagenesis of the organism by using a Drosophila melanogaster mariner-based transposon. To determine the efficiency of transposition, we have analyzed pigmentation mutants from the transposon mutant library. In addition to insertions in four known genes in the pathway of pigment biosynthesis, two insertions in novel genes were identified in our mutant library. One of these is in a putative inhibitor of the carotenoid biosynthesis pathway. The second unexpected insertion is in an intergenic region between two genes homologous to Rv2603c and Rv2604c of M. tuberculosis. In addition to a pigmentation defect, this mutant showed increased susceptibility to singlet oxygen and grew poorly in murine macrophages. Complementation with M. tuberculosis genomic DNA encompassing Rv2603c to Rv2606c corrected the pigmentation and growth defects of the mutant. These data demonstrate the utility of mariner-based transposon mutagenesis of M. marinum and that M. marinum can be used to study the function of M. tuberculosis genes involved in intracellular survival and replication.

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Section: Resultsmentioning

confidence: 96%

Transposon Mutagenesis ofMycobacterium marinumIdentifies a Locus Linking Pigmentation and Intracellular Survival

Gao¹,

Groger²,

Cox

et al. 2003

Infect Immun

106

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“…The trees show that the sequences from C. tepidum (including that of CrtC; data not shown) are not closely related to the sequences from Chloroflexus aurantiacus or any other organism. A CrtU desaturase produces aromatic carotenoids in the actinomycetes Mycobacterium aurum (56), Streptomyces griseus (36), and Brevibacterium linens (35) and in C. tepidum (this work; see below). Surprisingly, CrtU homologs were also identified in four cyanobacteria (Fig.…”

Section: Identification Of Genes Involved In Carotenoid Biosynthesismentioning

confidence: 99%

Genetic Manipulation of Carotenoid Biosynthesis in the Green Sulfur Bacterium Chlorobium tepidum

Frigaard¹,

Maresca²,

Yunker³

et al. 2004

J Bacteriol

100

116

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The green sulfur bacterium Chlorobium tepidum is a strict anaerobe and an obligate photoautotroph. On the basis of sequence similarity with known enzymes or sequence motifs, nine open reading frames encoding putative enzymes of carotenoid biosynthesis were identified in the genome sequence of C. tepidum, and all nine genes were inactivated. Analysis of the carotenoid composition in the resulting mutants allowed the genes encoding the following six enzymes to be identified: phytoene synthase (crtB/CT1386), phytoene desaturase (crtP/CT0807), -carotene desaturase (crtQ/CT1414), ␥-carotene desaturase (crtU/CT0323), carotenoid 1,2-hydratase (crtC/CT0301), and carotenoid cis-trans isomerase (crtH/CT0649). Three mutants (CT0180, CT1357, and CT1416 mutants) did not exhibit a discernible phenotype. The carotenoid biosynthetic pathway in C. tepidum is similar to that in cyanobacteria and plants by converting phytoene into lycopene using two plant-like desaturases (CrtP and CrtQ) and a plant-like cis-trans isomerase (CrtH) and thus differs from the pathway known in all other bacteria. In contrast to the situation in cyanobacteria and plants, the construction of a crtB mutant completely lacking carotenoids demonstrates that carotenoids are not essential for photosynthetic growth of green sulfur bacteria. However, the bacteriochlorophyll a contents of mutants lacking colored carotenoids (crtB, crtP, and crtQ mutants) were decreased from that of the wild type, and these mutants exhibited a significant growth rate defect under all light intensities tested. Therefore, colored carotenoids may have both structural and photoprotection roles in green sulfur bacteria. The ability to manipulate the carotenoid composition so dramatically in C. tepidum offers excellent possibilities for studying the roles of carotenoids in the light-harvesting chlorosome antenna and iron-sulfur-type (photosystem I-like) reaction center. The phylogeny of carotenogenic enzymes in green sulfur bacteria and green filamentous bacteria is also discussed.

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“…Mycobacterial pigments are generally yellow or orange and most have been confirmed as carotenoids [171]. While carotenoid genetics has been best studied in plants, the key enzymes of the pathway have been identified in bacteria, including mycobacteria [172][173][174]. There are two classes of carotenoids in bacteria, carotenes and xanthophylls, the latter of which contain oxygen.…”

Section: Carotenoidsmentioning

confidence: 99%

Metabolism of Plasma Membrane Lipids in Mycobacteria and Corynebacteria

Crellin¹,

Luo²,

Morita³

2013

Lipid Metabolism

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Structural and functional analysis of the gene cluster encoding carotenoid biosynthesis in Mycobacterium aurum A+

Cited by 23 publications

References 22 publications

Transposon Mutagenesis ofMycobacterium marinumIdentifies a Locus Linking Pigmentation and Intracellular Survival

Transposon Mutagenesis ofMycobacterium marinumIdentifies a Locus Linking Pigmentation and Intracellular Survival

Genetic Manipulation of Carotenoid Biosynthesis in the Green Sulfur Bacterium Chlorobium tepidum

Metabolism of Plasma Membrane Lipids in Mycobacteria and Corynebacteria

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