Genetic Characterization of the Carotenoid
Biosynthetic Pathway in Methylobacterium extorquens AM1 and
Isolation of a Colorless
Mutant

ABSTRACT Genomic searches were used to reconstruct the putative carotenoid biosynthesis pathway in the pink-pigmented facultative methylotroph Methylobacterium extorquens AM1. Four genes for putative phytoene desaturases were identified. A colorless mutant was obtained by transposon mutagenesis, and the insertion was shown to be in one of the putative phytoene desaturase genes. Mutations in the other three did not affect color. The tetracycline marker was removed from the original transposon mutant, resulting in a pigment-free strain with wild-type growth properties useful as a tool for future experiments.

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Genome Mining Reveals Two Missing CrtP and AldH Enzymes in the C30 Carotenoid Biosynthesis Pathway in Planococcus faecalis AJ003T

Molecules ◽

10.3390/molecules25245892 ◽

2020 ◽

Vol 25 (24) ◽

pp. 5892

Author(s):

Jun Ho Lee ◽

Jin Won Kim ◽

Pyung Cheon Lee

Keyword(s):

Escherichia Coli ◽

Biosynthetic Pathway ◽

Genome Mining ◽

Carotenoid Biosynthesis ◽

Biosynthesis Pathway ◽

Gene Encoding ◽

A Genome ◽

Genes Encoding ◽

Carotenoid Biosynthesis Pathway ◽

Carotenoid Pathway

Planococcus faecalis AJ003T produces glycosyl-4,4′-diaponeurosporen-4′-ol-4-oic acid as its main carotenoid. Five carotenoid pathway genes were presumed to be present in the genome of P. faecalis AJ003T; however, 4,4-diaponeurosporene oxidase (CrtP) was non-functional, and a gene encoding aldehyde dehydrogenase (AldH) was not identified. In the present study, a genome mining approach identified two missing enzymes, CrtP2 and AldH2454, in the glycosyl-4,4′-diaponeurosporen-4′-ol-4-oic acid biosynthetic pathway. Moreover, CrtP2 and AldH enzymes were functional in heterologous Escherichia coli and generated two carotenoid aldehydes (4,4′-diapolycopene-dial and 4,4′-diaponeurosporene-4-al) and two carotenoid carboxylic acids (4,4′-diaponeurosporenoic acid and 4,4′-diapolycopenoic acid). Furthermore, the genes encoding CrtP2 and AldH2454 were located at a distance the carotenoid gene cluster of P. faecalis.

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Molecular characterization of four morphological mutants of Neurospora crassa

Dhaka University Journal of Biological Sciences ◽

10.3329/dujbs.v23i1.19831 ◽

2014 ◽

Vol 23 (1) ◽

pp. 85-91

Author(s):

Nasrin Akter ◽

Ahashan Habib ◽

Salina Parvin Beauty ◽

Tahsina Rahim ◽

Mohammad Nurul Islam

Keyword(s):

Neurospora Crassa ◽

Uv Light ◽

Carotenoid Biosynthesis ◽

Biosynthesis Pathway ◽

Molecular Features ◽

Albino Mutant ◽

Morphological Mutants ◽

Banding Profile ◽

Carotenoid Biosynthesis Pathway

Four morphological mutants (albino, ropy, conidial band and buff) of Neurospora crassa were characterized based on morphological features and molecular markers. The mycelial color of mutants buff, ropy and conidial band were more or less orange like wild parents. Albino mutant showed colorless mycelium. The germination time of conidia of wild and other mutants ranged from 5 to 7 days while in albino it was 12 days. Esterase and acid phosphatase isozymes analysis of the N. crassa mutants clearly indicated that mutation altered the carotenoid biosynthesis pathway creating the albino mutant due to the effect UV light. Most of the mutants viz; albino, conidial band and buff showed characteristic RAPD banding profile. However, no band was found in wild EmA, Ema and mutant ropy. Highest number of RAPD bands were found in albino. The mutant albino showed very different morphological and molecular features from the rest specimens. DOI: http://dx.doi.org/10.3329/dujbs.v23i1.19831 Dhaka Univ. J. Biol. Sci. 23(1): 85-91, 2014

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Complete Genome Sequences of Six Measles Virus Strains

Genome Announcements ◽

10.1128/genomea.00184-18 ◽

2018 ◽

Vol 6 (13) ◽

Cited By ~ 1

Author(s):

My V. T. Phan ◽

Claudia M. E. Schapendonk ◽

Bas B. Oude Munnink ◽

Marion P. G. Koopmans ◽

Rik L. de Swart ◽

...

Keyword(s):

Next Generation Sequencing ◽

Complete Genome ◽

Measles Virus ◽

Genetic Characterization ◽

Critical Component ◽

Wild Type ◽

Genome Sequences ◽

Virus Strains ◽

Generation Sequencing

ABSTRACT Genetic characterization of wild-type measles virus (MV) strains is a critical component of measles surveillance and molecular epidemiology. We have obtained complete genome sequences of six MV strains belonging to different genotypes, using random-primed next generation sequencing.

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Metabolic Flux in Both the Purine Mononucleotide and Histidine Biosynthetic Pathways Can Influence Synthesis of the Hydroxymethyl Pyrimidine Moiety of Thiamine in Salmonella enterica

Journal of Bacteriology ◽

10.1128/jb.184.22.6130-6137.2002 ◽

2002 ◽

Vol 184 (22) ◽

pp. 6130-6137 ◽

Cited By ~ 26

Author(s):

Shara Allen ◽

Julie L. Zilles ◽

Diana M. Downs

Keyword(s):

Metabolic Flux ◽

Genetic Characterization ◽

Molecular Genetic ◽

Thiamine Pyrophosphate ◽

Wild Type ◽

Regulatory Pathway ◽

Informational Suppressors ◽

Pyrimidine Moiety ◽

Molecular Genetic Characterization

ABSTRACT Together, the biosyntheses of histidine, purines, and thiamine pyrophosphate (TPP) contain examples of convergent, divergent, and regulatory pathway integration. Mutations in two purine biosynthetic genes (purI and purH) affect TPP biosynthesis due to flux through the purine and histidine pathways. The molecular genetic characterization of purI mutants and their respective pseudorevertants resulted in the conclusion that <1% of the wild-type activity of the PurI enzyme was sufficient for thiamine but not for purine synthesis. The respective pseudorevertants were found to be informational suppressors. In addition, it was shown that accumulation of the purine intermediate aminoimidazole carboxamide ribotide inhibits thiamine synthesis, specifically affecting the conversion of aminoimidazole ribotide to hydroxymethyl pyrimidine.

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Genetic characterization of Rhizobium sp. strain TAL1145 that nodulates tree legumes

Canadian Journal of Microbiology ◽

10.1139/m94-034 ◽

1994 ◽

Vol 40 (3) ◽

pp. 208-215 ◽

Cited By ~ 16

Author(s):

M. L. C. George ◽

J. P. W. Young ◽

D. Borthakur

Keyword(s):

Rhizobium Leguminosarum ◽

Genetic Characterization ◽

Rhizobium Meliloti ◽

Wild Type ◽

Tree Legumes ◽

Wide Range ◽

The Common ◽

Rrna Sequences ◽

Rhizobium Sp

Rhizobium sp. strain TALI 145 nodulates Leucaena ieucocephaia and Phaseolus vulgaris, in addition to a wide range of tropical tree legumes. Six overlapping clones that complemented nodulation defects in leucaena and bean rhizobia were isolated and a 40-kb map of the symbiosis region was constructed. The common nod and nifA genes were situated approximately 17 kb apart, with the nodlJ genes in between. These clones enabled a derivative of TAL1145 carrying a partially deleted pSym to form ineffective nodules on both leucaena and bean, and a similar derivative of Rhizobium etli TAL182 to form ineffective nodules on bean. When two representative clones, pUHR9 and pUHR114, were each transferred to wild-type rhizobial strains, they allowed ineffective nodulation by Rhizobium meliloti on both leucaena and bean and by Rhizobium leguminosarum bv. viciae on bean. Transconjugants of R. leguminosarum bv. trifolii formed effective nodules on leucaena and ineffective nodules on bean. Tn5 mutagenesis of the symbiosis region resulted in a variety of nodulation and fixation phenotypes on leucaena and bean. On the basis of 16S rRNA sequences, TAL1145 was found to be distinct from both R. tropici and NGR234, the two groups of leucaena symbionts that were previously described.Key words: Rhizobium, Leucaena leucocephala, nodulation, nitrogen fixation.

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EPR study of thylakoid membrane dynamics in mutants of the carotenoid biosynthesis pathway of Synechocystis sp. PCC6803.

Acta Biochimica Polonica ◽

10.18388/abp.2012_2178 ◽

2012 ◽

Vol 59 (1) ◽

Cited By ~ 4

Author(s):

Kinga Kłodawska ◽

Przemysław Malec ◽

Mihály Kis ◽

Zoltán Gombos ◽

Kazimierz Strzałka

Keyword(s):

Optimal Growth ◽

Carotenoid Biosynthesis ◽

Growth Conditions ◽

Thylakoid Membranes ◽

Membrane Dynamics ◽

Biosynthesis Pathway ◽

Light Regimes ◽

Genes Encoding ◽

Splitting Parameter ◽

Carotenoid Biosynthesis Pathway

EPR spectroscopy using 5-doxylstearic acid (5-SASL) and 16-doxylstearic acid (16-SASL) spin probes was used to study the fluidity of thylakoid membranes. These were isolated from wild type Synechocystis and from several mutants in genes encoding selected enzymes of the carotenoid biosynthesis pathway and/or acyl-lipid desaturases. Cyanobacteria were cultivated at 25°C and 35°C under different light regimes: photoautotrophically (PAG) and/or in light-activated heterotrophic conditions (LAHG). The relative fluidity of membranes was estimated from EPR spectra based on the empirical outermost splitting parameter in a temperature range from 15°C to 40°C. Our findings demonstrate that in native thylakoid membranes the elimination of xanthophylls decreased fluidity in the inner membrane region under optimal growth conditions (25°C) and increased it under sublethal heat stress (35°C). This indicated that the overall fluidity of native photosynthetic membranes in cyanobacteria may be influenced by the ratio of polar to non-polar carotenoid pools under different environmental conditions.

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