{"title":"植物镁脱螯酶及其细菌同源物在植物体内和体外的活性检验","authors":"","doi":"10.1016/j.plaphy.2024.109073","DOIUrl":null,"url":null,"abstract":"<div><p>Chlorophyll <em>a</em> serves as a photosynthetic pigment in plants. Its degradation is initiated by the extraction of the central Mg by the Mg-dechelatase enzyme, which is encoded by <em>Stay-Green</em> (<em>SGR</em>). Plant <em>SGR</em> is believed to be derived from bacterial <em>SGR</em> homolog obtained through horizontal gene transfer into photosynthetic eukaryotes. However, it is not known how the bacterial SGR homolog was modified to function in plants. To assess its adaptation mechanism in plants, a bacterial <em>SGR</em> homolog derived from the <em>Anaerolineae</em> bacterium SM23_63 was introduced into plants. It was found that the bacterial <em>SGR</em> homolog metabolized chlorophyll in plants. However, its chlorophyll catabolic activity was lower than that of plant <em>SGR</em>. Recombinant proteins of the bacterial <em>SGR</em> homolog exhibited higher activity than those of the plant <em>SGR</em>. The reduced chlorophyll catabolic activity of bacterial <em>SGR</em> homologs in plants may be associated with low hydrophobicity of the entrance to the catalytic site compared to that of plant <em>SGR</em>. This hinders the enzyme access to chlorophyll, which is localized in hydrophobic environments. This study offers insights into the molecular changes underlying the optimization of enzyme function.</p></div>","PeriodicalId":20234,"journal":{"name":"Plant Physiology and Biochemistry","volume":null,"pages":null},"PeriodicalIF":6.1000,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Activity examination of plant Mg-dechelatase and its bacterial homolog in plants and in vitro\",\"authors\":\"\",\"doi\":\"10.1016/j.plaphy.2024.109073\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Chlorophyll <em>a</em> serves as a photosynthetic pigment in plants. Its degradation is initiated by the extraction of the central Mg by the Mg-dechelatase enzyme, which is encoded by <em>Stay-Green</em> (<em>SGR</em>). Plant <em>SGR</em> is believed to be derived from bacterial <em>SGR</em> homolog obtained through horizontal gene transfer into photosynthetic eukaryotes. However, it is not known how the bacterial SGR homolog was modified to function in plants. To assess its adaptation mechanism in plants, a bacterial <em>SGR</em> homolog derived from the <em>Anaerolineae</em> bacterium SM23_63 was introduced into plants. It was found that the bacterial <em>SGR</em> homolog metabolized chlorophyll in plants. However, its chlorophyll catabolic activity was lower than that of plant <em>SGR</em>. Recombinant proteins of the bacterial <em>SGR</em> homolog exhibited higher activity than those of the plant <em>SGR</em>. The reduced chlorophyll catabolic activity of bacterial <em>SGR</em> homologs in plants may be associated with low hydrophobicity of the entrance to the catalytic site compared to that of plant <em>SGR</em>. This hinders the enzyme access to chlorophyll, which is localized in hydrophobic environments. This study offers insights into the molecular changes underlying the optimization of enzyme function.</p></div>\",\"PeriodicalId\":20234,\"journal\":{\"name\":\"Plant Physiology and Biochemistry\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":6.1000,\"publicationDate\":\"2024-08-23\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Plant Physiology and Biochemistry\",\"FirstCategoryId\":\"99\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0981942824007411\",\"RegionNum\":2,\"RegionCategory\":\"生物学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"PLANT SCIENCES\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Plant Physiology and Biochemistry","FirstCategoryId":"99","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0981942824007411","RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"PLANT SCIENCES","Score":null,"Total":0}
Activity examination of plant Mg-dechelatase and its bacterial homolog in plants and in vitro
Chlorophyll a serves as a photosynthetic pigment in plants. Its degradation is initiated by the extraction of the central Mg by the Mg-dechelatase enzyme, which is encoded by Stay-Green (SGR). Plant SGR is believed to be derived from bacterial SGR homolog obtained through horizontal gene transfer into photosynthetic eukaryotes. However, it is not known how the bacterial SGR homolog was modified to function in plants. To assess its adaptation mechanism in plants, a bacterial SGR homolog derived from the Anaerolineae bacterium SM23_63 was introduced into plants. It was found that the bacterial SGR homolog metabolized chlorophyll in plants. However, its chlorophyll catabolic activity was lower than that of plant SGR. Recombinant proteins of the bacterial SGR homolog exhibited higher activity than those of the plant SGR. The reduced chlorophyll catabolic activity of bacterial SGR homologs in plants may be associated with low hydrophobicity of the entrance to the catalytic site compared to that of plant SGR. This hinders the enzyme access to chlorophyll, which is localized in hydrophobic environments. This study offers insights into the molecular changes underlying the optimization of enzyme function.
期刊介绍:
Plant Physiology and Biochemistry publishes original theoretical, experimental and technical contributions in the various fields of plant physiology (biochemistry, physiology, structure, genetics, plant-microbe interactions, etc.) at diverse levels of integration (molecular, subcellular, cellular, organ, whole plant, environmental). Opinions expressed in the journal are the sole responsibility of the authors and publication does not imply the editors'' agreement.
Manuscripts describing molecular-genetic and/or gene expression data that are not integrated with biochemical analysis and/or actual measurements of plant physiological processes are not suitable for PPB. Also "Omics" studies (transcriptomics, proteomics, metabolomics, etc.) reporting descriptive analysis without an element of functional validation assays, will not be considered. Similarly, applied agronomic or phytochemical studies that generate no new, fundamental insights in plant physiological and/or biochemical processes are not suitable for publication in PPB.
Plant Physiology and Biochemistry publishes several types of articles: Reviews, Papers and Short Papers. Articles for Reviews are either invited by the editor or proposed by the authors for the editor''s prior agreement. Reviews should not exceed 40 typewritten pages and Short Papers no more than approximately 8 typewritten pages. The fundamental character of Plant Physiology and Biochemistry remains that of a journal for original results.