MSMEG_3955 from Mycobacterium smegmatis is a FMN bounded homotrimeric NAD(P)H:Flavin mononucleotide (FMN) oxidoreductase

Abstract Background Tuberculosis (TB) remains an important public health problem since it is the major cause of elevated morbidity and mortality globally. Previous works have shown that Mycobacterium tuberculosis (Mtb); the prime causative agent of the deadly disease has dormancy survival regulator...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Neha Khosla, Seema Madhumal Thayil, Rajinder Kaur, Anup Kumar Kesavan
Formato: article
Lenguaje:EN
Publicado: BMC 2021
Materias:
Acceso en línea:https://doaj.org/article/d82b49475d7e46019cbd8a612c9a64b3
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
id oai:doaj.org-article:d82b49475d7e46019cbd8a612c9a64b3
record_format dspace
spelling oai:doaj.org-article:d82b49475d7e46019cbd8a612c9a64b32021-11-21T12:05:33ZMSMEG_3955 from Mycobacterium smegmatis is a FMN bounded homotrimeric NAD(P)H:Flavin mononucleotide (FMN) oxidoreductase10.1186/s12866-021-02330-y1471-2180https://doaj.org/article/d82b49475d7e46019cbd8a612c9a64b32021-11-01T00:00:00Zhttps://doi.org/10.1186/s12866-021-02330-yhttps://doaj.org/toc/1471-2180Abstract Background Tuberculosis (TB) remains an important public health problem since it is the major cause of elevated morbidity and mortality globally. Previous works have shown that Mycobacterium tuberculosis (Mtb); the prime causative agent of the deadly disease has dormancy survival regulator (DosR) regulon, a two-component regulatory system which controls the transcription of more than 50 genes. However, the structure and detailed functions of these DosR regulated genes are largely undetermined. Out of many DosR regulon genes, Rv3131 gets up regulated in hypoxic conditions and was believed to encode for a nitroreductase flavoprotein. The utilization of mycobacteria-specific model systems has greatly added to our understanding of the molecular mechanisms involved in the life cycle and pathogenesis of Mtb. Results In this study the non-pathogenic mycobacterial model organism Mycobacterium smegmatis (Msmeg) was used to reveal the structure and function of MSMEG_3955; which is a homologue of Rv3131 from Mtb. Using chromatography and spectroscopy techniques it was revealed that cofactor flavin mononucleotide (FMN) was bound to flavoprotein MSMEG_3955. Consistent with the homology modelling predictions, Circular Dichroism (CD) analysis indicated that the MSMEG_3955 is composed of 39.3% α-helix and 24.9% β-pleated sheets. In contrast to the current notions, the enzymatic assays performed in the present study revealed that MSMEG_3955 was not capable of reducing nitro substrates but showed NADPH dependent FMN oxidoreductase activity. Also, gel permeation chromatography, dynamic light scattering and native acidic gels showed that MSMEG_3955 exists as a homotrimer. Furthermore, the presence of NADPH dependent FMN oxidoreductase and homotrimeric existence could be an alternative function of the protein to help the bacteria survive in dormant state or may be involved in other biochemical pathways. Conclusion MSMEG_3955 is a FMN bound flavoprotein, which exits as a trimer under in vitro conditions. There is no disulphide linkages in between the three protomers of the homotrimer MSMEG_3955. It has a NADPH dependent FMN oxidoreductase activity.Neha KhoslaSeema Madhumal ThayilRajinder KaurAnup Kumar KesavanBMCarticleMicrobiologyQR1-502ENBMC Microbiology, Vol 21, Iss 1, Pp 1-12 (2021)
institution DOAJ
collection DOAJ
language EN
topic Microbiology
QR1-502
spellingShingle Microbiology
QR1-502
Neha Khosla
Seema Madhumal Thayil
Rajinder Kaur
Anup Kumar Kesavan
MSMEG_3955 from Mycobacterium smegmatis is a FMN bounded homotrimeric NAD(P)H:Flavin mononucleotide (FMN) oxidoreductase
description Abstract Background Tuberculosis (TB) remains an important public health problem since it is the major cause of elevated morbidity and mortality globally. Previous works have shown that Mycobacterium tuberculosis (Mtb); the prime causative agent of the deadly disease has dormancy survival regulator (DosR) regulon, a two-component regulatory system which controls the transcription of more than 50 genes. However, the structure and detailed functions of these DosR regulated genes are largely undetermined. Out of many DosR regulon genes, Rv3131 gets up regulated in hypoxic conditions and was believed to encode for a nitroreductase flavoprotein. The utilization of mycobacteria-specific model systems has greatly added to our understanding of the molecular mechanisms involved in the life cycle and pathogenesis of Mtb. Results In this study the non-pathogenic mycobacterial model organism Mycobacterium smegmatis (Msmeg) was used to reveal the structure and function of MSMEG_3955; which is a homologue of Rv3131 from Mtb. Using chromatography and spectroscopy techniques it was revealed that cofactor flavin mononucleotide (FMN) was bound to flavoprotein MSMEG_3955. Consistent with the homology modelling predictions, Circular Dichroism (CD) analysis indicated that the MSMEG_3955 is composed of 39.3% α-helix and 24.9% β-pleated sheets. In contrast to the current notions, the enzymatic assays performed in the present study revealed that MSMEG_3955 was not capable of reducing nitro substrates but showed NADPH dependent FMN oxidoreductase activity. Also, gel permeation chromatography, dynamic light scattering and native acidic gels showed that MSMEG_3955 exists as a homotrimer. Furthermore, the presence of NADPH dependent FMN oxidoreductase and homotrimeric existence could be an alternative function of the protein to help the bacteria survive in dormant state or may be involved in other biochemical pathways. Conclusion MSMEG_3955 is a FMN bound flavoprotein, which exits as a trimer under in vitro conditions. There is no disulphide linkages in between the three protomers of the homotrimer MSMEG_3955. It has a NADPH dependent FMN oxidoreductase activity.
format article
author Neha Khosla
Seema Madhumal Thayil
Rajinder Kaur
Anup Kumar Kesavan
author_facet Neha Khosla
Seema Madhumal Thayil
Rajinder Kaur
Anup Kumar Kesavan
author_sort Neha Khosla
title MSMEG_3955 from Mycobacterium smegmatis is a FMN bounded homotrimeric NAD(P)H:Flavin mononucleotide (FMN) oxidoreductase
title_short MSMEG_3955 from Mycobacterium smegmatis is a FMN bounded homotrimeric NAD(P)H:Flavin mononucleotide (FMN) oxidoreductase
title_full MSMEG_3955 from Mycobacterium smegmatis is a FMN bounded homotrimeric NAD(P)H:Flavin mononucleotide (FMN) oxidoreductase
title_fullStr MSMEG_3955 from Mycobacterium smegmatis is a FMN bounded homotrimeric NAD(P)H:Flavin mononucleotide (FMN) oxidoreductase
title_full_unstemmed MSMEG_3955 from Mycobacterium smegmatis is a FMN bounded homotrimeric NAD(P)H:Flavin mononucleotide (FMN) oxidoreductase
title_sort msmeg_3955 from mycobacterium smegmatis is a fmn bounded homotrimeric nad(p)h:flavin mononucleotide (fmn) oxidoreductase
publisher BMC
publishDate 2021
url https://doaj.org/article/d82b49475d7e46019cbd8a612c9a64b3
work_keys_str_mv AT nehakhosla msmeg3955frommycobacteriumsmegmatisisafmnboundedhomotrimericnadphflavinmononucleotidefmnoxidoreductase
AT seemamadhumalthayil msmeg3955frommycobacteriumsmegmatisisafmnboundedhomotrimericnadphflavinmononucleotidefmnoxidoreductase
AT rajinderkaur msmeg3955frommycobacteriumsmegmatisisafmnboundedhomotrimericnadphflavinmononucleotidefmnoxidoreductase
AT anupkumarkesavan msmeg3955frommycobacteriumsmegmatisisafmnboundedhomotrimericnadphflavinmononucleotidefmnoxidoreductase
_version_ 1718419274240884736