[Objective]The study aimed to investigate the effects of the amino acids of aspartate family on the biosynthesis of CoQ10 in Rhodpseudomonas palustris J001.[Method]The impacts of amino acids of this family on the bios...[Objective]The study aimed to investigate the effects of the amino acids of aspartate family on the biosynthesis of CoQ10 in Rhodpseudomonas palustris J001.[Method]The impacts of amino acids of this family on the biosynthesis of CoQ10 in Rhodopseudomnas palustris J001 were investigated by feeding these amino acids at the end of the logarithmic phase during incubation,which aim was for the optimization of the fermentation medium and genetic improvement of the strain for CoQ10 production.[Result]The results showed that feeding proper amount of methione(125 mg/L)could increase CoQ10 production by 20.2%,but feeding of lysine(above 500 mg/L),threonine(above 400 mg/L)and/or isoleucine(above 400 mg/L)repressed the biosynthesis of CoQ10.The results indicated that the aspartate kinase is subject to feedback inhibition or repression by lysine,threonine and isoleucine in the strain,which was unfavorable to the formation of methioine and then caused the decrease of CoQ10 production.[Conclusion]Lysine,threonine and isoleucine auxotrophic mutants with resistance to analogues of lysine,threonine and isoleucine could increase the production of CoQ10.展开更多
Plant virus causes massive crop losses globally.However,there is currently no effective measure to control plant viral disease.Previously,we identify an antiviral protein Rhp-PSP,produced by the bacterial Rhodopseudom...Plant virus causes massive crop losses globally.However,there is currently no effective measure to control plant viral disease.Previously,we identify an antiviral protein Rhp-PSP,produced by the bacterial Rhodopseudomonas palustris strain JSC-3b.In this study,we discover that the antiviral activity of Rhp-PSP relies on its endoribonuclease activity.Converting the arginine(R)residue at position 129 onto alanine(A)abolishs its endoribonuclease activity on coat protein(CP)RNA of tobacco mosaic virus(TMV),consequentially,compromises the antiviral activity of Rhp-PSP.Further investigation demonstrates that,the mutant Rhp-PSP^(R129A)is unable to form the homotrimer as the wild type,indicating the importance of quaternary junction for the endoribonuclease activity.Overexpression of Rhp-PSP in Nicotiana benthamiana significantly enhances the resistance against TMV of seedlings,while expression of Rhp-PSP^(R129A)did not,confirming that endoribonuclease activity is responsible for the antiviral activity of Rhp-PSP.In addition,foliar spray of Rhp-PSP solution on tomato and pepper plants significantly reduces the disease index of viral diseases,indicating that Rhp-PSP shows potential to develop antiviral agent in practice.展开更多
Rhodopseudomonas palustris, one of purple nonsulfur photosynthetic bacteria, fixes carbon dioxide via Calvin-Benson cycle and has been shown previously to express form I and form II ribulose-1,5-bisphosphate carboxyla...Rhodopseudomonas palustris, one of purple nonsulfur photosynthetic bacteria, fixes carbon dioxide via Calvin-Benson cycle and has been shown previously to express form I and form II ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO). The gene cbbM, which encodes the form II enzyme from Rhodopseudomonas palustris, has been subcloned and sequenced. The deduced amino acid sequence is highly with the form II RubisCO from photosynthetic bacteria, including Rhodospirillum rubrum (PDB ID: 9rub), but appears to be more distantly related to the large subunit of the form I RubisCO found in photosynthetic bacteria, chemoautotrophic bacteria and higher plants. Several regions highly conserved among L 8S 8 and L x enzymes correspond with regions previously implicated in catalytic activity and subunit interactions.展开更多
文摘[Objective]The study aimed to investigate the effects of the amino acids of aspartate family on the biosynthesis of CoQ10 in Rhodpseudomonas palustris J001.[Method]The impacts of amino acids of this family on the biosynthesis of CoQ10 in Rhodopseudomnas palustris J001 were investigated by feeding these amino acids at the end of the logarithmic phase during incubation,which aim was for the optimization of the fermentation medium and genetic improvement of the strain for CoQ10 production.[Result]The results showed that feeding proper amount of methione(125 mg/L)could increase CoQ10 production by 20.2%,but feeding of lysine(above 500 mg/L),threonine(above 400 mg/L)and/or isoleucine(above 400 mg/L)repressed the biosynthesis of CoQ10.The results indicated that the aspartate kinase is subject to feedback inhibition or repression by lysine,threonine and isoleucine in the strain,which was unfavorable to the formation of methioine and then caused the decrease of CoQ10 production.[Conclusion]Lysine,threonine and isoleucine auxotrophic mutants with resistance to analogues of lysine,threonine and isoleucine could increase the production of CoQ10.
基金supported by the National Key R&D Program of China(2022YFD1400700)the Key Research and Development Program of Hunan Province,China(2022NK2014)+2 种基金the Hunan Natural Science Foundation,China(2022JJ40234)the Agricultural Science and Technology Innovation Fund Project of Hunan Province,China(2022CX1)the Changsha Natural Science Foundation,China(kq2202338).
文摘Plant virus causes massive crop losses globally.However,there is currently no effective measure to control plant viral disease.Previously,we identify an antiviral protein Rhp-PSP,produced by the bacterial Rhodopseudomonas palustris strain JSC-3b.In this study,we discover that the antiviral activity of Rhp-PSP relies on its endoribonuclease activity.Converting the arginine(R)residue at position 129 onto alanine(A)abolishs its endoribonuclease activity on coat protein(CP)RNA of tobacco mosaic virus(TMV),consequentially,compromises the antiviral activity of Rhp-PSP.Further investigation demonstrates that,the mutant Rhp-PSP^(R129A)is unable to form the homotrimer as the wild type,indicating the importance of quaternary junction for the endoribonuclease activity.Overexpression of Rhp-PSP in Nicotiana benthamiana significantly enhances the resistance against TMV of seedlings,while expression of Rhp-PSP^(R129A)did not,confirming that endoribonuclease activity is responsible for the antiviral activity of Rhp-PSP.In addition,foliar spray of Rhp-PSP solution on tomato and pepper plants significantly reduces the disease index of viral diseases,indicating that Rhp-PSP shows potential to develop antiviral agent in practice.
文摘Rhodopseudomonas palustris, one of purple nonsulfur photosynthetic bacteria, fixes carbon dioxide via Calvin-Benson cycle and has been shown previously to express form I and form II ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO). The gene cbbM, which encodes the form II enzyme from Rhodopseudomonas palustris, has been subcloned and sequenced. The deduced amino acid sequence is highly with the form II RubisCO from photosynthetic bacteria, including Rhodospirillum rubrum (PDB ID: 9rub), but appears to be more distantly related to the large subunit of the form I RubisCO found in photosynthetic bacteria, chemoautotrophic bacteria and higher plants. Several regions highly conserved among L 8S 8 and L x enzymes correspond with regions previously implicated in catalytic activity and subunit interactions.
