Pantothenate synthesis in plants

Raman, Srivatsan; Rathinasabapathi, Bala

doi:10.1016/j.plantsci.2004.06.019

Cited by 43 publications

(26 citation statements)

References 55 publications

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“…pyroglutamate and b-Ala) showed marked reductions. The latter is in agreement with likewise repressed pantothenate, the essential precursor of CoA (Raman and Rathinasabapathi, 2004). Intriguingly, classical markers of senescence processes such as RNA degradation are increased, since the free nucleobases adenine, cytosine, uracil, and thymine accumulated in MtSucS1-as mycorrhizae (average +1.22/+1.24), in concert with an enhanced level of Rib at least in line as12.…”

Section: Mtsucs1 Reduction Is Correlated With Changes In Steady-statesupporting

confidence: 74%

Knockdown of the Symbiotic Sucrose Synthase MtSucS1 Affects Arbuscule Maturation and Maintenance in Mycorrhizal Roots of Medicago truncatula

et al. 2009

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The relevance of the symbiosis-induced Medicago truncatula sucrose synthase gene MtSucS1 for an efficient arbuscular mycorrhiza (AM) was studied using two independent antisense lines that displayed up to 10-fold reduced SucS1 levels in roots. Mycorrhizal MtSucS1-reduced lines exhibited an overall stunted aboveground growth under inorganic phosphorus limitation. Apart from a reduced plant height, shoot weight, and leaf development, a delayed flowering, resulting in a lower seed yield, was observed. In addition, the root-to-shoot and root weight ratios increased significantly. Gene expression studies demonstrated a major reversion of AM-associated transcription, exhibiting a significant repression of well-known plant AM marker and mycosymbiont genes, together indicating a diminished AM fungus colonization of MtSucS1-antisense lines. Concomitantly, gas chromatography-mass spectrometry-based metabolite profiling revealed that mycorrhizal MtSucS1-reduced lines were affected in important nodes of the carbon, nitrogen, and phosphorus metabolism, accentuating a physiological significance of MtSucS1 for AM. In fact, antisensing MtSucS1 provoked an impaired fungal colonization within the less abundant infected regions, evident from strongly reduced frequencies of internal hyphae, vesicles, and arbuscules. Moreover, arbuscules were early senescing, accompanied with a reduced development of mature arbuscules. This defective mycorrhiza status correlated with reduced phosphorus and nitrogen levels and was proportional to the extent of MtSucS1 knockdown. Together, our results point to an important role for MtSucS1 in the establishment and maintenance of arbuscules in the AM symbiosis.

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Section: Mtsucs1 Reduction Is Correlated With Changes In Steady-statesupporting

confidence: 74%

Knockdown of the Symbiotic Sucrose Synthase MtSucS1 Affects Arbuscule Maturation and Maintenance in Mycorrhizal Roots of Medicago truncatula

et al. 2009

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“…Based on BRENDA (Schomburg et al 2013), TAIR (Lamesch et al 2011), and PlantCyc and MetaCyc databases (Caspi et al 2012), and references in the text (color figure online) Plant amino acid-derived vitamins 811 intermediary of both its synthesis and degradation (Webb et al 2004;Chakauya et al 2006). In plants, there is evidence for the synthesis of b-alanine (a non-protein amino acid) from a number of precursor pathways: polyamine degradation, uracil degradation and synthesis from propionate (Kupke et al 2003;Raman and Rathinasabapathi 2004;Chakauya et al 2006). Amino acids can also be dynamically incorporated and removed from a vitamin with a regulatory role.…”

Section: Amino Acids In Vitamin Biosynthesismentioning

confidence: 99%

Plant amino acid-derived vitamins: biosynthesis and function

Miret

Munné‐Bosch

2013

Amino Acids

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Vitamins are essential organic compounds for humans, having lost the ability to de novo synthesize them. Hence, they represent dietary requirements, which are covered by plants as the main dietary source of most vitamins (through food or livestock's feed). Most vitamins synthesized by plants present amino acids as precursors (B1, B2, B3, B5, B7, B9 and E) and are therefore linked to plant nitrogen metabolism. Amino acids play different roles in their biosynthesis and metabolism, either incorporated into the backbone of the vitamin or as amino, sulfur or one-carbon group donors. There is a high natural variation in vitamin contents in crops and its exploitation through breeding, metabolic engineering and agronomic practices can enhance their nutritional quality. While the underlying biochemical roles of vitamins as cosubstrates or cofactors are usually common for most eukaryotes, the impact of vitamins B and E in metabolism and physiology can be quite different on plants and animals. Here, we first aim at giving an overview of the biosynthesis of amino acid-derived vitamins in plants, with a particular focus on how this knowledge can be exploited to increase vitamin contents in crops. Second, we will focus on the functions of these vitamins in both plants and animals (and humans in particular), to unravel common and specific roles for vitamins in evolutionary distant organisms, in which these amino acid-derived vitamins play, however, an essential role.

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“…Type I PanKs (PanK-I) are found exclusively in eubacterial species and are exemplified by the Escherichia coli enzyme encoded by the coaA gene (46,47). The second type of PanK (PanK-II) is found mainly in eukaryotes, including yeast and various fungi, plants, and mammals (12,(41)(42)(43). Interestingly, PanKs from a few gram-positive bacteria, such as Staphylococcus aureus (PanK Sa ) and several bacilli, are also included in this group based on sequence homology, although the bacterial enzymes exhibit certain catalytic characteristics different from their eukaryotic counterparts (15,31).…”

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confidence: 99%

Crystal Structure of a Type III Pantothenate Kinase: Insight into the Mechanism of an Essential Coenzyme A Biosynthetic Enzyme Universally Distributed in Bacteria

et al. 2006

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Pantothenate kinase (PanK) catalyzes the first step in the five-step universal pathway of coenzyme A (CoA) biosynthesis, a key transformation that generally also regulates the intracellular concentration of CoA through feedback inhibition. A novel PanK protein encoded by the gene coaX was recently identified that is distinct from the previously characterized type I PanK (exemplified by the Escherichia coli coaA-encoded PanK protein) and type II eukaryotic PanKs and is not inhibited by CoA or its thioesters. This type III PanK, or PanK-III, is widely distributed in the bacterial kingdom and accounts for the only known PanK in many pathogenic species, such as Helicobacter pylori, Bordetella pertussis, and Pseudomonas aeruginosa. Here we report the first crystal structure of a type III PanK, the enzyme from Thermotoga maritima (PanK Tm ), solved at 2.0-Å resolution. The structure of PanK Tm reveals that type III PanKs belong to the acetate and sugar kinase/heat shock protein 70/actin (ASKHA) protein superfamily and that they retain the highly conserved active site motifs common to all members of this superfamily. Comparative structural analysis of the PanK Tm active site configuration and mutagenesis of three highly conserved active site aspartates identify these residues as critical for PanK-III catalysis. Furthermore, the analysis also provides an explanation for the lack of CoA feedback inhibition by the enzyme. Since PanK-III adopts a different structural fold from that of the E. coli PanK-which is a member of the "P-loop kinase"superfamily-this finding represents yet another example of convergent evolution of the same biological function from a different protein ancestor.Pantothenate kinase (PanK; EC 2.7.1.33) catalyzes the ATPdependent phosphorylation of pantothenate (vitamin B 5 ) to give 4Ј-phosphopantothenate. This reaction represents the first and committed step in the universal biosynthetic pathway of coenzyme A (CoA) (6, 27, 32). Because CoA is a ubiquitous and essential cofactor in all organisms, genes coding for the five enzymes that make up this pathway-including PanK-are essential for their survival and growth (6,27).Three distinct types of PanK, as differentiated by primary sequence analysis and kinetic properties, have been characterized so far. Type I PanKs (PanK-I) are found exclusively in eubacterial species and are exemplified by the Escherichia coli enzyme encoded by the coaA gene (46, 47). The second type of PanK (PanK-II) is found mainly in eukaryotes, including yeast and various fungi, plants, and mammals (12, 41-43). Interestingly, PanKs from a few gram-positive bacteria, such as Staphylococcus aureus (PanK Sa ) and several bacilli, are also included in this group based on sequence homology, although the bacterial enzymes exhibit certain catalytic characteristics different from their eukaryotic counterparts (15,31). Recently, a third type of PanK (PanK-III) was identified which represents the only known pantothenate kinase activity in many pathogenic bacteria, including Helicobacter pylor...

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Pantothenate synthesis in plants

Cited by 43 publications

References 55 publications

Knockdown of the Symbiotic Sucrose Synthase MtSucS1 Affects Arbuscule Maturation and Maintenance in Mycorrhizal Roots of Medicago truncatula

Knockdown of the Symbiotic Sucrose Synthase MtSucS1 Affects Arbuscule Maturation and Maintenance in Mycorrhizal Roots of Medicago truncatula

Plant amino acid-derived vitamins: biosynthesis and function

Crystal Structure of a Type III Pantothenate Kinase: Insight into the Mechanism of an Essential Coenzyme A Biosynthetic Enzyme Universally Distributed in Bacteria

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