1nbu | pdb_00001nbu

7,8-Dihydroneopterin Aldolase Complexed with Product From Mycobacterium Tuberculosis

spinqualitylabelsall models 1nbu, resolution 1.60Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1nbu is a 8 chain structure with sequence from "bacillus_tuberculosis"_(zopf_1883)_klein_1884 "bacillus tuberculosis" (zopf 1883) klein 1884. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: PH2 Gene: FOLB OR RV3607C OR MT3712.1 OR MTCY07H7B.15 ("Bacillus tuberculosis" (Zopf 1883) Klein 1884) Activity: Dihydroneopterin aldolase, with EC number 4.1.2.25 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [FOLB_MYCTU] Catalyzes the conversion of 7,8-dihydroneopterin to 6-hydroxymethyl-7,8-dihydropterin (By similarity). Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Folate derivatives are essential cofactors in the biosynthesis of purines, pyrimidines and amino acids across all forms of life. Mammals uptake folate from their diets, whereas most bacteria must synthesize folate de novo. Therefore, the enzymes in the folate biosynthetic pathway are attractive drug targets against bacterial pathogens such as Mycobacterium tuberculosis, the cause of the world's most deadly infectious disease, tuberculosis (TB). M.tuberculosis 7,8-dihydroneopterin aldolase (Mtb FolB, DHNA) is the second enzyme in the folate biosynthetic pathway, which catalyzes the conversion of 7,8-dihydroneopterin to 6-hydroxymethyl-7,8-dihydropterin and glycoaldehyde. The 1.6A X-ray crystal structure of Mtb FolB complexed with its product, 6-hydroxymethyl-7,8-dihydropterin, reveals an octameric assembly similar to that seen in crystal structures of other FolB homologs. However, the 2.5A crystal structure of unliganded Mtb FolB reveals a novel tetrameric oligomerization state, with only partially formed active sites. A substrate induced conformational change appears to be necessary to convert the inactive tetramer to the active octamer. Ultracentrifugation confirmed that in solution unliganded Mtb FolB is mainly tetrameric and upon addition of substrate FolB is predominantly octameric. Kinetic analysis of substrate binding gives a Hill coefficient of 2.0, indicating positive cooperativity. We hypothesize that Mtb FolB displays cooperativity in substrate binding to regulate the cellular concentration of 7,8-dihydroneopterin, so that it may function not only as a precursor to folate but also as an antioxidant for the survival of M.tuberculosis against host defenses. Regulation by oligomerization in a mycobacterial folate biosynthetic enzyme.,Goulding CW, Apostol MI, Sawaya MR, Phillips M, Parseghian A, Eisenberg D J Mol Biol. 2005 May 27;349(1):61-72. Epub 2005 Apr 2. PMID:15876368 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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