Distribution and Functional Analysis of the Two Types of 8-vinyl Reductase Involved in Chlorophyll Biosynthesis in Marine Cyanobacteria

2021 ◽  
Author(s):  
Haruka Suehiro ◽  
Ryouichi Tanaka ◽  
Hisashi Ito
Keyword(s):  
Chlorophyll Biosynthesis ◽  
Marine Cyanobacteria ◽  
Biosynthesis Pathway ◽  
Genomic Comparison ◽  
Marine Cyanobacterium ◽  
Photosynthetic Organisms ◽  
Chlorophyll Precursor ◽  
Vinyl Group ◽  
Vinyl Reductase

Abstract In the chlorophyll biosynthesis pathway, the 8-vinyl group of the chlorophyll precursor is reduced to an ethyl group by 8-vinyl reductase. Two isozymes of 8-vinyl reductase have been described in oxygenic photosynthetic organisms: one encoded by BciA and another by BciB. Only BciB contains an [Fe-S] cluster and most cyanobacteria harbor this form; whereas a few contain BciA. Given this disparity in distribution, cyanobacterial BciA has remained largely overlooked, which has limited understanding of chlorophyll biosynthesis in these microorganisms. Here, we reveal that cyanobacterial BciA encodes a functional 8-vinyl reductase, as evidenced by measuring the in vitro activity of recombinant Synechococcus and Acaryochloris BciA. Genomic comparison revealed that BciB had been replaced by BciA during evolution of the marine cyanobacterium Synechococcus, and coincided with replacement of Fe-superoxide dismutase (SOD) with Ni-SOD. These findings imply that the acquisition of BciA confers an adaptive advantage to cyanobacteria living in low-iron oceanic environments.

Molecular Cloning and Characterization Analysis of 3,8-Divinyl Protochlorophyllide a 8-Vinyl Reductase Gene from Dunaliella parva

2011 ◽  
Vol 347-353 ◽  
pp. 3203-3206
Author(s):  
Chang Hua Shang ◽  
Shun Ni Zhu ◽  
Zhen Hong Yuan ◽  
Zhong Ming Wang
Keyword(s):  
Sequence Similarity ◽  
Volvox Carteri ◽  
Reading Frame ◽  
Photosynthetic Organisms ◽  
Untranslated Sequence ◽  
Oleaginous Microalgae ◽  
Dunaliella Parva ◽  
Reductase Gene ◽  
Vinyl Group ◽  
Vinyl Reductase

The vast majority of photosynthetic organisms utilize monovinyl chlorophyll for their photosynthetic reactions. For the biosynthesis of monovinyl chlorophyll, the reduction of the 8-vinyl group which is located on the B-ring of the macrocycle is essential. 3,8-Divinyl protochlorophyllide a 8-vinyl reductase (DVR) catalyzes the reduction of 8-vinyl group on the tetrapyrrole to an ethyl group, which is necessary for monovinyl chlorophyll (Chl) synthesis. The former studies indicated the DVR could enhance photosynthesis. The full-length cDNA encoding DVR was obtained from oleaginous microalgae Dunaliella parva, which include 1326 bp open reading frame (ORF), 22 bp 5′-untranslated sequence and 383 bp 3′-untranslated sequence. Dunaliella parva DVR showed the highest sequence similarity with the DVR from Chlamydomonas reinhardtii and Volvox carteri. The Dunaliella parva DVR also showed wide similarity with other species.

scholarly journals Elucidation of the core betalain biosynthesis pathway in Amaranthus tricolor

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yu-Cheng Chang ◽  
Yi-Ching Chiu ◽  
Nai-Wen Tsao ◽  
Yuan-Lin Chou ◽  
Choon-Meng Tan ◽  
...  
Keyword(s):  
Transcriptome Analysis ◽  
Natural Antioxidants ◽  
Biosynthesis Pathway ◽  
Comparative Transcriptome ◽  
Amaranthus Tricolor ◽  
Enzymatic Assays ◽  
Comparative Transcriptome Analysis ◽  
Elevated Expression ◽  
Green Coloration

AbstractAmaranthus tricolor L., a vegetable Amaranthus species, is an economically important crop containing large amounts of betalains. Betalains are natural antioxidants and can be classified into betacyanins and betaxanthins, with red and yellow colors, respectively. A. tricolor cultivars with varying betalain contents, leading to striking red to green coloration, have been commercially produced. However, the molecular differences underlying betalain biosynthesis in various cultivars of A. tricolor remain largely unknown. In this study, A. tricolor cultivars with different colors were chosen for comparative transcriptome analysis. The elevated expression of AmCYP76AD1 in a red-leaf cultivar of A. tricolor was proposed to play a key role in producing red betalain pigments. The functions of AmCYP76AD1, AmDODAα1, AmDODAα2, and AmcDOPA5GT were also characterized through the heterologous engineering of betalain pigments in Nicotiana benthamiana. Moreover, high and low L-DOPA 4,5-dioxygenase activities of AmDODAα1 and AmDODAα2, respectively, were confirmed through in vitro enzymatic assays. Thus, comparative transcriptome analysis combined with functional and enzymatic studies allowed the construction of a core betalain biosynthesis pathway of A. tricolor. These results not only provide novel insights into betalain biosynthesis and evolution in A. tricolor but also provide a basal framework for examining genes related to betalain biosynthesis among different species of Amaranthaceae.

scholarly journals Two Unrelated 8-Vinyl Reductases Ensure Production of Mature Chlorophylls in Acaryochloris marina

2016 ◽  
Vol 198 (9) ◽  
pp. 1393-1400 ◽  
Author(s):  
Guangyu E. Chen ◽  
Andrew Hitchcock ◽  
Philip J. Jackson ◽  
Roy R. Chaudhuri ◽  
Mark J. Dickman ◽  
...  
Keyword(s):  
Transcriptional Control ◽  
Sequence Similarity ◽  
Open Reading Frames ◽  
High Sequence Similarity ◽  
Content Type ◽  
Ethyl Group ◽  
Acaryochloris Marina ◽  
Vinyl Group ◽  
Vinyl Reductase ◽  
Reading Frames

ABSTRACTThe major photopigment of the cyanobacteriumAcaryochloris marinais chlorophylld, while its direct biosynthetic precursor, chlorophylla, is also present in the cell. These pigments, along with the majority of chlorophylls utilized by oxygenic phototrophs, carry an ethyl group at the C-8 position of the molecule, having undergone reduction of a vinyl group during biosynthesis. Two unrelated classes of 8-vinyl reductase involved in the biosynthesis of chlorophylls are known to exist, BciA and BciB. The genome ofAcaryochloris marinacontains open reading frames (ORFs) encoding proteins displaying high sequence similarity to BciA or BciB, although they are annotated as genes involved in transcriptional control (nmrA) and methanogenesis (frhB), respectively. These genes were introduced into an 8-vinyl chlorophylla-producing ΔbciBstrain ofSynechocystissp. strain PCC 6803, and both were shown to restore synthesis of the pigment with an ethyl group at C-8, demonstrating their activities as 8-vinyl reductases. We propose thatnmrAandfrhBbe reassigned asbciAandbciB, respectively; transcript and proteomic analysis ofAcaryochloris marinareveal that bothbciAandbciBare expressed and their encoded proteins are present in the cell, possibly in order to ensure that all synthesized chlorophyll pigment carries an ethyl group at C-8. Potential reasons for the presence of two 8-vinyl reductases in this strain, which is unique for cyanobacteria, are discussed.IMPORTANCEThe cyanobacteriumAcaryochloris marinais the best-studied phototrophic organism that uses chlorophylldfor photosynthesis. Unique among cyanobacteria sequenced to date, its genome contains ORFs encoding two unrelated enzymes that catalyze the reduction of the C-8 vinyl group of a precursor molecule to an ethyl group. Carrying a reduced C-8 group may be of particular importance to organisms containing chlorophylld. Plant genomes also contain orthologs of both of these genes; thus, the bacterial progenitor of the chloroplast may also have contained bothbciAandbciB.

Investigation of tyrosinase inhibition by some 1,2,4 triazole derivative compounds: in vitro and in silico mechanisms

2018 ◽  
Vol 44 (4) ◽  
pp. 473-481
Author(s):  
Elif Ayazoglu Demir ◽  
Ahmet Colak ◽  
Aylin Kalfa ◽  
Ahmet Yasar ◽  
Olcay Bekircan ◽  
...  
Keyword(s):  
Critical Role ◽  
Docking Studies ◽  
Biosynthesis Pathway ◽  
Mushroom Tyrosinase ◽  
Tyrosinase Inhibitor ◽  
Effective Inhibitor ◽  
Tyrosinase Inhibition ◽  
Triazole Derivative

Abstract Background Tyrosinase plays a central role in the biosynthesis pathway of melanin pigment. Melanin protects human skin against radiation and its unusual levels cause some skin disorders such as pregnancy scar, oldness spots and melanoma. Tyrosinase has also been linked to Parkinson’s and other neurodegenerative diseases. In addition, melanin plays a critical role as a defense molecule for insects during wound healing and is important for their life. Therefore, determination of inhibitor molecules for tyrosinase has a promising potential for therapies of some diseases and is an alternative method for keeping insects under control. Material and methods In this study, 1-hepthyl-3-(4-methoxybenzyl)-4H-1,2,4-triazole-5-one derivative (A6, A8, A15) and 3-(4-chlorophenyl)- 5-(4-methoxybenzyl)-4H-1,2,4-triazole (B5, B9, B13) derivative compounds were evaluated in terms of their potential for mushroom tyrosinase inhibition. IC50 values of these six molecules were determined. Results It was seen that B9 molecule was the most effective inhibitor. Docking studies also nearly supported this end result. Tyrosinase inhibition type and Ki value were found to be uncompetitive and 370.7±0.3 μM, respectively, in the presence of B9 compound. Conclusion These results suggest that B9 compound is a potential tyrosinase inhibitor.

scholarly journals Gatorbulin-1, a distinct cyclodepsipeptide chemotype, targets a seventh tubulin pharmacological site

2021 ◽  
Vol 118 (9) ◽  
pp. e2021847118
Author(s):  
Susan Matthew ◽  
Qi-Yin Chen ◽  
Ranjala Ratnayake ◽  
Charles S. Fermaintt ◽  
Daniel Lucena-Agell ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Wide Spectrum ◽  
Targeted Chemotherapy ◽  
Structural Determination ◽  
Marine Cyanobacterium ◽  
Microtubule Stabilization ◽  
Biochemical Studies ◽  
Β Tubulin

Tubulin-targeted chemotherapy has proven to be a successful and wide spectrum strategy against solid and liquid malignancies. Therefore, new ways to modulate this essential protein could lead to new antitumoral pharmacological approaches. Currently known tubulin agents bind to six distinct sites at α/β-tubulin either promoting microtubule stabilization or depolymerization. We have discovered a seventh binding site at the tubulin intradimer interface where a novel microtubule-destabilizing cyclodepsipeptide, termed gatorbulin-1 (GB1), binds. GB1 has a unique chemotype produced by a marine cyanobacterium. We have elucidated this dual, chemical and mechanistic, novelty through multidimensional characterization, starting with bioactivity-guided natural product isolation and multinuclei NMR-based structure determination, revealing the modified pentapeptide with a functionally critical hydroxamate group; and validation by total synthesis. We have investigated the pharmacology using isogenic cancer cell screening, cellular profiling, and complementary phenotypic assays, and unveiled the underlying molecular mechanism by in vitro biochemical studies and high-resolution structural determination of the α/β-tubulin−GB1 complex.

scholarly journals Bornyl Diphosphate Synthase From Cinnamomum burmanni and Its Application for (+)-Borneol Biosynthesis in Yeast

2021 ◽  
Vol 9 ◽  
Author(s):  
Rui Ma ◽  
Ping Su ◽  
Juan Guo ◽  
Baolong Jin ◽  
Qing Ma ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Biosynthetic Pathway ◽  
Main Product ◽  
Microbial Fermentation ◽  
Biosynthesis Pathway ◽  
Analgesic Effects ◽  
Pathway Reconstruction ◽  
Key Enzyme ◽  
Shake Flasks

(+)-Borneol is a desirable monoterpenoid with effective anti-inflammatory and analgesic effects that is known as soft gold. (+)-bornyl diphosphate synthase is the key enzyme in the (+)-borneol biosynthesis pathway. Despite several reported (+)-bornyl diphosphate synthase genes, relatively low (+)-borneol production hinders the attempts to synthesize it using microbial fermentation. Here, we identified the highly specific (+)-bornyl diphosphate synthase CbTPS1 from Cinnamomum burmanni. An in vitro assay showed that (+)-borneol was the main product of CbTPS1 (88.70% of the total products), and the Km value was 5.11 ± 1.70 μM with a kcat value of 0.01 s–1. Further, we reconstituted the (+)-borneol biosynthetic pathway in Saccharomyces cerevisiae. After tailored truncation and adding Kozak sequences, the (+)-borneol yield was improved by 96.33-fold to 2.89 mg⋅L–1 compared with the initial strain in shake flasks. This work is the first reported attempt to produce (+)-borneol by microbial fermentation. It lays a foundation for further pathway reconstruction and metabolic engineering production of this valuable natural monoterpenoid.

Alkane production by the marine cyanobacterium Synechococcus sp. NKBG15041c possessing the α-olefin biosynthesis pathway

2014 ◽  
Vol 99 (3) ◽  
pp. 1521-1529 ◽  
Author(s):  
Tomoko Yoshino ◽  
Yue Liang ◽  
Daichi Arai ◽  
Yoshiaki Maeda ◽  
Toru Honda ◽  
...  
Keyword(s):  
Biosynthesis Pathway ◽  
Marine Cyanobacterium ◽  
Synechococcus Sp

Caffeine Metabolism in High and Low Caffeine Containing Cultivars of Camellia sinensis

1995 ◽  
Vol 50 (9-10) ◽  
pp. 602-607 ◽  
Author(s):  
Hiroshi Ashihara ◽  
Hisayo Shimizu ◽  
Yoshiyuki Takeda ◽  
Takeo Suzuki ◽  
Fiona M. Gillies ◽  
...  
Keyword(s):  
Camellia Sinensis ◽  
Adenine Nucleotides ◽  
Vitro Activity ◽  
Biosynthesis Pathway ◽  
Rapid Rate ◽  
In Vitro Activity ◽  
Caffeine Content ◽  
Caffeine Biosynthesis ◽  
Caffeine Metabolism

Abstract The metabolism of [8-14C ]adenine and [2-14C]caffeine was examined in leaf segments from flush shoots of tea cultivars with high and low caffeine content. The caffeine biosynthesis pathway from AMP via theobromine was operative in both high and low caffeine containing cultivars. There was a m ore rapid rate of caffeine biosynthesis from [8-14C ]adenine in the high caffeine cultivars while the rate of degradation of both adenine nucleotides and caffeine into CO2 was greatest in cultivars with a low endogenous caffeine content. Cell-free p reparations from tea shoots contained an N-methyltransferase, that is a keyenzyme in the caffeine biosynthesis pathway; more in-vitro activity was detected in preparations from high caffeine containing cultivars. The data obtained suggest that the high caffeine containing cultivars have a more rapid rate of caffeine biosynthesis and a slower rate of caffeine catabolism than cultivars with a low endogenous caffeine content

scholarly journals Arginine-deprivation–induced oxidative damage sterilizes Mycobacterium tuberculosis

2018 ◽  
Vol 115 (39) ◽  
pp. 9779-9784 ◽  
Author(s):  
Sangeeta Tiwari ◽  
Andries J. van Tonder ◽  
Catherine Vilchèze ◽  
Vitor Mendes ◽  
Sherine E. Thomas ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Dna Damage ◽  
Mycobacterium Tuberculosis ◽  
De Novo ◽  
Target Space ◽  
Biosynthesis Pathway ◽  
Arginine Biosynthesis ◽  
Arginine Deprivation

Reactive oxygen species (ROS)-mediated oxidative stress and DNA damage have recently been recognized as contributing to the efficacy of most bactericidal antibiotics, irrespective of their primary macromolecular targets. Inhibitors of targets involved in both combating oxidative stress as well as being required for in vivo survival may exhibit powerful synergistic action. This study demonstrates that the de novo arginine biosynthetic pathway in Mycobacterium tuberculosis (Mtb) is up-regulated in the early response to the oxidative stress-elevating agent isoniazid or vitamin C. Arginine deprivation rapidly sterilizes the Mtb de novo arginine biosynthesis pathway mutants ΔargB and ΔargF without the emergence of suppressor mutants in vitro as well as in vivo. Transcriptomic and flow cytometry studies of arginine-deprived Mtb have indicated accumulation of ROS and extensive DNA damage. Metabolomics studies following arginine deprivation have revealed that these cells experienced depletion of antioxidant thiols and accumulation of the upstream metabolite substrate of ArgB or ArgF enzymes. ΔargB and ΔargF were unable to scavenge host arginine and were quickly cleared from both immunocompetent and immunocompromised mice. In summary, our investigation revealed in vivo essentiality of the de novo arginine biosynthesis pathway for Mtb and a promising drug target space for combating tuberculosis.

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