BACKGROUND: 3,4-Dihydroxy-2-butanone-4-phosphate synthase catalyzes a commitment step in the biosynthesis of riboflavin. On the enzyme, ribulose 5-phosphate is converted to 3,4-dihydroxy-2-butanone 4-phosphate and formate in steps involving enolization, ketonization, dehydration, skeleton rearrangement, and formate elimination. The enzyme is absent in humans and an attractive target for the discovery of antimicrobials for pathogens incapable of acquiring sufficient riboflavin from their hosts. The homodimer of 23 kDa subunits requires Mg(2+) for activity. RESULTS: The first three-dimensional structure of the enzyme was determined at 1.4 A resolution using the multiwavelength anomalous diffraction (MAD) method on Escherichia coli protein crystals containing gold. The protein consists of an alpha + beta fold having a complex linkage of beta strands. Intersubunit contacts are mediated by numerous hydrophobic interactions and three hydrogen bond networks. CONCLUSIONS: A proposed active site was identified on the basis of amino acid residues that are conserved among the enzyme from 19 species. There are two well-separated active sites per dimer, each of which comprise residues from both subunits. In addition to three arginines and two threonines, which may be used for recognizing the phosphate group of the substrate, the active site consists of three glutamates, two aspartates, two histidines, and a cysteine which may provide the means for general acid and base catalysis and for coordinating the Mg(2+) cofactor within the active site.
BACKGROUND: 3,4-Dihydroxy-2-butanone-4-phosphate synthase catalyzes a commitment step in the biosynthesis of riboflavin. On the enzyme, ribulose 5-phosphate is converted to 3,4-dihydroxy-2-butanone 4-phosphate and formate in steps involving enolization, ketonization, dehydration, skeleton rearrangement, and formate elimination. The enzyme is absent in humans and an attractive target for the discovery of antimicrobials for pathogens incapable of acquiring sufficient riboflavin from their hosts. The homodimer of 23 kDa subunits requires Mg(2+) for activity. RESULTS: The first three-dimensional structure of the enzyme was determined at 1.4 A resolution using the multiwavelength anomalous diffraction (MAD) method on Escherichia coli protein crystals containing gold. The protein consists of an alpha + beta fold having a complex linkage of beta strands. Intersubunit contacts are mediated by numerous hydrophobic interactions and three hydrogen bond networks. CONCLUSIONS: A proposed active site was identified on the basis of amino acid residues that are conserved among the enzyme from 19 species. There are two well-separated active sites per dimer, each of which comprise residues from both subunits. In addition to three arginines and two threonines, which may be used for recognizing the phosphate group of the substrate, the active site consists of three glutamates, two aspartates, two histidines, and a cysteine which may provide the means for general acid and base catalysis and for coordinating the Mg(2+) cofactor within the active site.
Authors: M J Kelly; L J Ball; C Krieger; Y Yu; M Fischer; S Schiffmann; P Schmieder; R Kühne; W Bermel; A Bacher; G Richter; H Oschkinat Journal: Proc Natl Acad Sci U S A Date: 2001-10-30 Impact factor: 11.205
Authors: James Kirby; Minobu Nishimoto; Ruthie W N Chow; Edward E K Baidoo; George Wang; Joel Martin; Wendy Schackwitz; Rossana Chan; Jeffrey L Fortman; Jay D Keasling Journal: Appl Environ Microbiol Date: 2014-10-17 Impact factor: 4.792
Authors: Ekaterina Morgunova; Boris Illarionov; Sabine Saller; Aleksander Popov; Thota Sambaiah; Adelbert Bacher; Mark Cushman; Markus Fischer; Rudolf Ladenstein Journal: Acta Crystallogr D Biol Crystallogr Date: 2010-08-13
Authors: Nikola Kenjić; Kathleen M Meneely; Daniel J Wherritt; Melissa C Denler; Timothy A Jackson; Graham R Moran; Audrey L Lamb Journal: J Am Chem Soc Date: 2022-07-08 Impact factor: 16.383