title: Polyprenyl phosphate biosynthesis in Mycobacterium tuberculosis and Mycobacterium smegmatis.
abstract: Mycobacterium smegmatis has been shown to contain two forms of polyprenyl phosphate (Pol-P), while Mycobacterium tuberculosis contains only one. Utilizing subcellular fractions from M. smegmatis and M. tuberculosis, we show that Pol-P synthesis is different in these species. The specific activities of the prenyl diphosphate synthases in M. tuberculosis are 10- to 100-fold lower than those in M. smegmatis. In M. smegmatis decaprenyl diphosphate and heptaprenyl diphosphate were the main products synthesized in vitro, whereas in M. tuberculosis only decaprenyl diphosphate was synthesized. The data from both organisms suggest that geranyl diphosphate is the allylic substrate for two distinct prenyl diphosphate synthases, one located in the cell membrane that synthesizes omega,E,Z-farnesyl diphosphate and the other present in the cytosol that synthesizes omega,E,E,E-geranylgeranyl diphosphate. In M. smegmatis, the omega,E, Z-farnesyl diphosphate is utilized by a membrane-associated prenyl diphosphate synthase activity to generate decaprenyl diphosphate, and the omega,E,E,E-geranylgeranyl diphosphate is utilized by a membrane-associated activity for the synthesis of the heptaprenyl diphosphate. In M. tuberculosis, however, omega,E,E,E-geranylgeranyl diphosphate is not utilized for the synthesis of heptaprenyl diphosphate. Thus, the difference in the compositions of the Pol-P of M. smegmatis and M. tuberculosis can be attributed to distinct enzymatic differences between these two organisms.
authors.affiliation: Department of Microbiology, Colorado State University, Fort Collins, Colorado 80523-1677, USA. dcrick@cvmbs.colostate.edu
authors.forename: D C
authors.initials: DC
authors.lastname: Crick
authors.forename: M C
authors.initials: MC
authors.lastname: Schulbach
authors.forename: E E
authors.initials: EE
authors.lastname: Zink
authors.forename: M
authors.initials: M
authors.lastname: Macchia
authors.forename: S
authors.initials: S
authors.lastname: Barontini
authors.forename: G S
authors.initials: GS
authors.lastname: Besra
authors.forename: P J
authors.initials: PJ
authors.lastname: Brennan
mesh_terms: D002462:Cell Membrane / Q000378:metabolism; D002855:Chromatography, Thin Layer; D003600:Cytosol / Q000378:metabolism; D015394:Molecular Structure; D020102:Mycobacterium smegmatis / Q000378:metabolism*; D009169:Mycobacterium tuberculosis / Q000378:metabolism*; D011106:Polyisoprenyl Phosphates / Q000096:biosynthesis* / Q000737:chemistry / Q000302:isolation & purification; D013045:Species Specificity
chemical_list: D011106:Polyisoprenyl Phosphates