title: Partial Saturation of Menaquinone inMycobacterium tuberculosis: Function and Essentiality of a Novel Reductase, MenJ.
abstract: Menaquinone (MK) with partially saturated isoprenyl moieties is found in a wide range of eubacteria and Archaea. In many Gram-positive organisms, including mycobacteria, it is the double bond found in the β-isoprene unit that is reduced. Mass spectral characterization of menaquinone from mycobacterial knockout strains and heterologous expression hosts demonstrates thatRv0561c(designatedmenJ) encodes an enzyme which reduces the β-isoprene unit of menaquinone inMycobacterium tuberculosis, forming the predominant form of menaquinone found in mycobacteria. MenJ is highly conserved in mycobacteria species but is not required for growth in culture. Disruption ofmenJreduces mycobacterial electron transport efficiency by 3-fold, but mycobacteria are able to maintain ATP levels by increasing the levels of the total menaquinone in the membrane; however, MenJ is required forM. tuberculosissurvival in host macrophages. Thus, MK with partially hydrogenated isoprenyl moieties represents a novel virulence factor and MenJ is a contextually essential enzyme and a potential drug target in pathogenic mycobacteria and other Gram-positive pathogens.
authors.affiliation: Department of Microbiology, Immunology and Pathology, Department of Chemistry, and Cell and Molecular Biology Program, Colorado State University , Fort Collins, Colorado 80523, United States.
authors.forename: Ashutosh
authors.initials: A
authors.lastname: Upadhyay
authors.affiliation: Department of Microbiology, Immunology and Pathology, Department of Chemistry, and Cell and Molecular Biology Program, Colorado State University , Fort Collins, Colorado 80523, United States.
authors.forename: Fabio L
authors.initials: FL
authors.lastname: Fontes
authors.affiliation: Department of Microbiology, Immunology and Pathology, Department of Chemistry, and Cell and Molecular Biology Program, Colorado State University , Fort Collins, Colorado 80523, United States.
authors.forename: Mercedes
authors.initials: M
authors.lastname: Gonzalez-Juarrero
authors.affiliation: Department of Microbiology, Immunology and Pathology, Department of Chemistry, and Cell and Molecular Biology Program, Colorado State University , Fort Collins, Colorado 80523, United States.
authors.forename: Michael R
authors.initials: MR
authors.lastname: McNeil
authors.affiliation: Department of Microbiology, Immunology and Pathology, Department of Chemistry, and Cell and Molecular Biology Program, Colorado State University , Fort Collins, Colorado 80523, United States.
authors.forename: Debbie C
authors.initials: DC
authors.lastname: Crans
authors.affiliation: Department of Microbiology, Immunology and Pathology, Department of Chemistry, and Cell and Molecular Biology Program, Colorado State University , Fort Collins, Colorado 80523, United States.
authors.forename: Mary
authors.initials: M
authors.lastname: Jackson
authors.affiliation: Department of Microbiology, Immunology and Pathology, Department of Chemistry, and Cell and Molecular Biology Program, Colorado State University , Fort Collins, Colorado 80523, United States.
authors.forename: Dean C
authors.initials: DC
authors.lastname: Crick