Cloning and characterization of a maize cDNA encoding phytoene desaturase, an enzyme of the carotenoid biosynthetic pathway

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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Biosynthesis of anandamide and N-palmitoylethanolamine by sequential actions of phospholipase A2 and lysophospholipase D

Biochemical Journal ◽

10.1042/bj20040031 ◽

2004 ◽

Vol 380 (3) ◽

pp. 749-756 ◽

Cited By ~ 143

Author(s):

Yong-Xin SUN ◽

Kazuhito TSUBOI ◽

Yasuo OKAMOTO ◽

Takeharu TONAI ◽

Makoto MURAKAMI ◽

...

Keyword(s):

Biosynthetic Pathway ◽

Brain Homogenate ◽

Wide Distribution ◽

Rat Tissues ◽

Lysophospholipase D ◽

Pla2 Enzyme ◽

First Time ◽

Hydrolysis Of ◽

The Brain

Anandamide (an endocannabinoid) and other bioactive long-chain NAEs (N-acylethanolamines) are formed by direct release from N-acyl-PE (N-acyl-phosphatidylethanolamine) by a PLD (phospholipase D). However, the possible presence of a two-step pathway from N-acyl-PE has also been suggested previously, which comprises (1) the hydrolysis of N-acyl-PE to N-acyl-lysoPE by PLA1/PLA2 enzyme(s) and (2) the release of NAEs from N-acyllysoPE by lysoPLD (lysophospholipase D) enzyme(s). In the present study we report for the first time the characterization of enzymes responsible for this pathway. The PLA1/PLA2 activity for N-palmitoyl-PE was found in various rat tissues, with the highest activity in the stomach. This stomach enzyme was identified as group IB sPLA2 (secretory PLA2), and its product was determined as N-acyl-1-acyl-lysoPE. Recombinant group IB, IIA and V of sPLA2s were also active with N-palmitoyl-PE, whereas group X sPLA2 and cytosolic PLA2α were inactive. In addition, we found wide distribution of lysoPLD activity generating N-palmitoylethanolamine from N-palmitoyl-lysoPE in rat tissues, with higher activities in the brain and testis. Based on several lines of enzymological evidence, the lysoPLD enzyme could be distinct from the known N-acyl-PE-hydrolysing PLD. sPLA2-IB dose dependently enhanced the production of N-palmitoylethanolamine from N-palmitoyl-PE in the brain homogenate showing the lysoPLD activity. N-Arachidonoyl-PE and N-arachidonoyl-lysoPE as anandamide precursors were also good substrates of sPLA2-IB and the lysoPLD respectively. These results suggest that the sequential actions of PLA2 and lysoPLD may constitute another biosynthetic pathway for NAEs, including anandamide.

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Structural and Biochemical Characterization of the Salicylyl-acyltranferase SsfX3 from a Tetracycline Biosynthetic Pathway

Journal of Biological Chemistry ◽

10.1074/jbc.m111.299859 ◽

2011 ◽

Vol 286 (48) ◽

pp. 41539-41551 ◽

Cited By ~ 10

Author(s):

Lauren B. Pickens ◽

Michael R. Sawaya ◽

Huma Rasool ◽

Inna Pashkov ◽

Todd O. Yeates ◽

...

Keyword(s):

Biosynthetic Pathway ◽

Biochemical Characterization

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Structural characterization of CalO1: a putative orsellinic acid methyltransferase in the calicheamicin-biosynthetic pathway

Acta Crystallographica Section D Biological Crystallography ◽

10.1107/s090744491100360x ◽

2011 ◽

Vol 67 (3) ◽

pp. 197-203 ◽

Cited By ~ 14

Author(s):

Aram Chang ◽

Shanteri Singh ◽

Craig A. Bingman ◽

Jon S. Thorson ◽

George N. Phillips

Keyword(s):

Structural Characterization ◽

Biosynthetic Pathway ◽

Orsellinic Acid

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Molecular Characterization of a Poly-β-Hydroxybutyrate-Producing Microbacterium Isolate

International Journal of Applied Sciences and Biotechnology ◽

10.3126/ijasbt.v3i2.12277 ◽

2015 ◽

Vol 3 (2) ◽

pp. 143-150 ◽

Cited By ~ 4

Author(s):

Yehia A. Osman ◽

Ahmed Abd Elrazak ◽

Wesam Khater ◽

EL-Shahat Nashy ◽

Attia Mohamadeen

Keyword(s):

Biosynthetic Pathway ◽

Nitrogen Deficiency ◽

Rrna Gene ◽

Excess Carbon ◽

Controlling Elements ◽

Tree Data ◽

Microbacterium Paraoxydans ◽

Coa Reductase ◽

Beta Hydroxybutyrate

Bacterial poly-β-hydroxybutyrate (PHB) is a natural, biodegradable polymer, which is accumulated in the cells as an energy reserve materialdue to depletion of nitrogen or phosphorous in the presence of excess carbon source. This polymer is foreseen to possess high industrialpotentiality and excellent alternative to the non-degradable petroleum-based plastics. In this study, we isolated and characterized a localbacterial strain WA81 which accumulated 18mg/L PHB after 72 h growth in mineral salt medium under nitrogen deficiency. The PHB granuleswere detected in the cells using TEM and the genes encode for this polymer were detected by oligonucleotide primers using PCR technology.The 16S rRNA gene nucleotide sequence for this isolate was used to construct a phylogentic tree against all available sequences in the GenBank.The phylogenetic tree data suggested that the closest type strain to the local bacterium is the Microbacterium paraoxydans CF36T and hencewe named it Microbacterium sp. strain WA81. Moreover, the set of enzymes responsible for the PHB biosynthetic pathway and their controllingelements were detected in this local isolate using PCR. The genes encode for the biosynthesis enzymes are phbA (β-ketothiolase), phbB(acetoacetly CoA reductase), phbC (PHB polymerase), while the genes encode for the controlling elements are phbP (phasin), phbZ (PHBdepolymerase). The novelty of this local bacterium lies in its ability to accumulate huge amounts of PHB in its cytoplasm and the presence ofa whole set of genes encode for the PHB biosynthetic and catabolic pathways of this polymer.Int J Appl Sci Biotechnol, Vol 3(2): 143-150 DOI: http://dx.doi.org/10.3126/ijasbt.v3i2.12277

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Expression, Purification, and Characterization of (R)-Sulfolactate Dehydrogenase (ComC) from the Rumen MethanogenMethanobrevibacter milleraeSM9

Archaea ◽

10.1155/2017/5793620 ◽

2017 ◽

Vol 2017 ◽

pp. 1-6

Author(s):

Yanli Zhang ◽

Linley R. Schofield ◽

Carrie Sang ◽

Debjit Dey ◽

Ron S. Ronimus

Keyword(s):

Biosynthetic Pathway ◽

Critical Role ◽

Reduction Reaction ◽

Coenzyme M ◽

Purification And Characterization ◽

The Third ◽

Optimal Activity ◽

Methyl Coenzyme M Reductase

(R)-Sulfolactate dehydrogenase (EC 1.1.1.337), termed ComC, is a member of an NADH/NADPH-dependent oxidoreductase family of enzymes that catalyze the interconversion of 2-hydroxyacids into their corresponding 2-oxoacids. The ComC reaction is reversible and in the biosynthetic direction causes the conversion of (R)-sulfolactate to sulfopyruvate in the production of coenzyme M (2-mercaptoethanesulfonic acid). Coenzyme M is an essential cofactor required for the production of methane by the methyl-coenzyme M reductase complex. ComC catalyzes the third step in the first established biosynthetic pathway of coenzyme M and is also involved in methanopterin biosynthesis. In this study, ComC fromMethanobrevibacter milleraeSM9 was cloned and expressed inEscherichia coliand biochemically characterized. Sulfopyruvate was the preferred substrate using the reduction reaction, with 31% activity seen for oxaloacetate and 0.2% seen forα-ketoglutarate. Optimal activity was observed at pH 6.5. The apparentKMfor coenzyme (NADH) was 55.1 μM, and for sulfopyruvate, it was 196 μM (for sulfopyruvate theVmaxwas 93.9 μmol min−1 mg−1andkcatwas 62.8 s−1). The critical role of ComC in two separate cofactor pathways makes this enzyme a potential means of developing methanogen-specific inhibitors for controlling ruminant methane emissions which are increasingly being recognized as contributing to climate change.

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