Christian Heryakusuma, Eric F Johnson, Endang Purwantini, Biswarup Mukhopadhyay
{"title":"jannaschi甲烷钙球菌f420依赖性亚硫酸盐还原酶(Fsr)的亚硝酸盐还原酶活性。","authors":"Christian Heryakusuma, Eric F Johnson, Endang Purwantini, Biswarup Mukhopadhyay","doi":"10.1099/acmi.0.000482.v3","DOIUrl":null,"url":null,"abstract":"<p><p><i>Methanocaldococcus jannaschii</i> (<i>Mj</i>), a hyperthermophilic and evolutionarily deeply rooted methanogenic archaeon from a deep-sea hydrothermal vent, produces F<sub>420</sub>-dependent sulphite reductase (Fsr) in response to exposure to sulphite. This enzyme allows <i>Mj</i> to detoxify sulphite, a potent inhibitor of methyl coenzyme-M reductase (Mcr), by reducing it to sulphide with reduced coenzyme F<sub>420</sub> (F<sub>420</sub>H<sub>2</sub>) as an electron donor; Mcr is essential for energy production for a methanogen. Fsr allows <i>Mj</i> to utilize sulphite as a sulphur source. Nitrite is another potent inhibitor of Mcr and is toxic to methanogens. It is reduced by most sulphite reductases. In this study, we report that <i>Mj</i>Fsr reduced nitrite to ammonia with F<sub>420</sub>H<sub>2</sub> with physiologically relevant <i>K</i> <sub>m</sub> values (nitrite, 8.9 µM; F<sub>420</sub>H<sub>2</sub>, 9.7 µM). The enzyme also reduced hydroxylamine with a <i>K</i> <sub>m</sub> value of 112.4 µM, indicating that it was an intermediate in the reduction of nitrite to ammonia. These results open the possibility that <i>Mj</i> could use nitrite as a nitrogen source if it is provided at a low concentration of the type that occurs in its habitat.</p>","PeriodicalId":6956,"journal":{"name":"Access Microbiology","volume":"5 4","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10202398/pdf/","citationCount":"0","resultStr":"{\"title\":\"Nitrite reductase activity in F<sub>420</sub>-dependent sulphite reductase (Fsr) from <i>Methanocaldococcus jannaschii</i>.\",\"authors\":\"Christian Heryakusuma, Eric F Johnson, Endang Purwantini, Biswarup Mukhopadhyay\",\"doi\":\"10.1099/acmi.0.000482.v3\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p><i>Methanocaldococcus jannaschii</i> (<i>Mj</i>), a hyperthermophilic and evolutionarily deeply rooted methanogenic archaeon from a deep-sea hydrothermal vent, produces F<sub>420</sub>-dependent sulphite reductase (Fsr) in response to exposure to sulphite. This enzyme allows <i>Mj</i> to detoxify sulphite, a potent inhibitor of methyl coenzyme-M reductase (Mcr), by reducing it to sulphide with reduced coenzyme F<sub>420</sub> (F<sub>420</sub>H<sub>2</sub>) as an electron donor; Mcr is essential for energy production for a methanogen. Fsr allows <i>Mj</i> to utilize sulphite as a sulphur source. Nitrite is another potent inhibitor of Mcr and is toxic to methanogens. It is reduced by most sulphite reductases. In this study, we report that <i>Mj</i>Fsr reduced nitrite to ammonia with F<sub>420</sub>H<sub>2</sub> with physiologically relevant <i>K</i> <sub>m</sub> values (nitrite, 8.9 µM; F<sub>420</sub>H<sub>2</sub>, 9.7 µM). The enzyme also reduced hydroxylamine with a <i>K</i> <sub>m</sub> value of 112.4 µM, indicating that it was an intermediate in the reduction of nitrite to ammonia. These results open the possibility that <i>Mj</i> could use nitrite as a nitrogen source if it is provided at a low concentration of the type that occurs in its habitat.</p>\",\"PeriodicalId\":6956,\"journal\":{\"name\":\"Access Microbiology\",\"volume\":\"5 4\",\"pages\":\"\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2023-01-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10202398/pdf/\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Access Microbiology\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.1099/acmi.0.000482.v3\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Access Microbiology","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1099/acmi.0.000482.v3","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Nitrite reductase activity in F420-dependent sulphite reductase (Fsr) from Methanocaldococcus jannaschii.
Methanocaldococcus jannaschii (Mj), a hyperthermophilic and evolutionarily deeply rooted methanogenic archaeon from a deep-sea hydrothermal vent, produces F420-dependent sulphite reductase (Fsr) in response to exposure to sulphite. This enzyme allows Mj to detoxify sulphite, a potent inhibitor of methyl coenzyme-M reductase (Mcr), by reducing it to sulphide with reduced coenzyme F420 (F420H2) as an electron donor; Mcr is essential for energy production for a methanogen. Fsr allows Mj to utilize sulphite as a sulphur source. Nitrite is another potent inhibitor of Mcr and is toxic to methanogens. It is reduced by most sulphite reductases. In this study, we report that MjFsr reduced nitrite to ammonia with F420H2 with physiologically relevant Km values (nitrite, 8.9 µM; F420H2, 9.7 µM). The enzyme also reduced hydroxylamine with a Km value of 112.4 µM, indicating that it was an intermediate in the reduction of nitrite to ammonia. These results open the possibility that Mj could use nitrite as a nitrogen source if it is provided at a low concentration of the type that occurs in its habitat.