title: Catalysis of an Essential Step in Vitamin B2 Biosynthesis by a Consortium of Broad Spectrum Hydrolases.
abstract: An enzyme catalysing the essential dephosphorylation of the riboflavin precursor, 5-amino-6-ribitylamino-2,4(1H,3H)-pyrimidinedione 5'-phosphate (6), was purified about 800-fold from a riboflavin-producing Bacillus subtilis strain, and was assigned as the translation product of the ycsE gene by mass spectrometry. YcsE is a member of the large haloacid dehalogenase (HAD) superfamily. The recombinant protein was expressed in Escherichia coli. It catalyses the hydrolysis of 6 (vmax , 12 μmol mg(-1)  min(-1) ; KM , 54 μm) and of FMN (vmax , 25 μmol mg(-1)  min(-1) ; KM , 135 μm). A ycsE deletion mutant of B. subtilis was not riboflavin dependent. Two additional proteins (YwtE, YitU) that catalyse the hydrolysis of 6 at appreciable rates were identified by screening 13 putative HAD superfamily members from B. subtilis. The evolutionary processes that have resulted in the handling of an essential step in the biosynthesis of an essential cofactor by a consortium of promiscuous enzymes require further analysis.
authors: Hamburg School of Food Science, Institute of Food Chemistry, University of Hamburg, Grindelallee 117, 20146, Hamburg, Germany.
authors: Sonja
authors: S
authors: Sarge
authors: Hamburg School of Food Science, Institute of Food Chemistry, University of Hamburg, Grindelallee 117, 20146, Hamburg, Germany.
authors: Ilka
authors: I
authors: Haase
authors: Hamburg School of Food Science, Institute of Food Chemistry, University of Hamburg, Grindelallee 117, 20146, Hamburg, Germany.
authors: Boris
authors: B
authors: Illarionov
authors: DSM Nutritional Products, P. O. Box 2676, 4002, Basel, Switzerland.
authors: Dietmar
authors: D
authors: Laudert
authors: DSM Nutritional Products, P. O. Box 2676, 4002, Basel, Switzerland.
authors: Hans-Peter
authors: HP
authors: Hohmann
authors: Hamburg School of Food Science, Institute of Food Chemistry, University of Hamburg, Grindelallee 117, 20146, Hamburg, Germany.
authors: Adelbert
authors: A
authors: Bacher
authors: Hamburg School of Food Science, Institute of Food Chemistry, University of Hamburg, Grindelallee 117, 20146, Hamburg, Germany. markus.fischer@uni-hamburg.de.
authors: Markus
authors: M
authors: Fischer
mesh_terms: D001412:Bacillus subtilis / Q000201:enzymology; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D055162:Biocatalysis; D004926:Escherichia coli / Q000378:metabolism; D006867:Hydrolases / Q000235:genetics / Q000378:metabolism; D006868:Hydrolysis; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics; D012256:Riboflavin / Q000096:biosynthesis* / Q000737:chemistry
chemical_list: D001426:Bacterial Proteins; D007527:Isoenzymes; D011994:Recombinant Proteins; D006867:Hydrolases; C034507:2-haloacid dehalogenase; D012256:Riboflavin
keywords: biosynthesis; haloacid dehalogenase; hydrolases; isoenzymes; vitamin B2