Biosynthesis of riboflavin: cloning, sequencing, and expression of the gene coding for 3,4-dihydroxy-2-butanone 4-phosphate synthase of Escherichia coli.
3,4-Dihydroxy-2-butanone 4-phosphate is biosynthesized from ribulose 5-phosphate and serves as the biosynthetic precursor for the xylene ring of riboflavin. The gene coding for 3,4-dihydroxy-2-butanone 4-phosphate synthase of Escherichia coli has been cloned and sequenced. The gene codes for a protein of 217 amino acid residues with a calculated molecular mass of 23,349.6 Da. The enzyme was purified to near homogeneity from a recombinant E. coli strain and had a specific activity of 1,700 nmol mg-1 h-1. The N-terminal amino acid sequence and the amino acid composition of the protein were in agreement with the deduced sequence. The molecular mass as determined by ion spray mass spectrometry was 23,351 +/- 2 Da, which is in agreement with the predicted mass. The previously reported loci htrP, "luxH-like," and ribB at 66 min of the E. coli chromosome are all identical to the gene coding for 3,4-dihydroxy-2-butanone 4-phosphate synthase, but their role had not been hitherto determined. Sequence homology indicates that gene luxH of Vibrio harveyi and the central open reading frame of the Bacillus subtilis riboflavin operon code for 3,4-dihydroxy-2-butanone 4-phosphate synthase.
Richter
G
G
Lehrstuhl für Organische Chemie und Biochemie, Technische Universität München, Garching, Germany.
Volk
R
R
Krieger
C
C
Lahm
H W
HW
Röthlisberger
U
U
Bacher
A
A
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics; D001483:Base Sequence; D002238:Carbohydrate Epimerases / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial; D006360:Heat-Shock Proteins / Q000235:genetics; D019751:Intramolecular Transferases; D008969:Molecular Sequence Data; D010957:Plasmids / Q000235:genetics; D012256:Riboflavin / Q000096:biosynthesis*; D012274:Ribulosephosphates / Q000378:metabolism; D016415:Sequence Alignment; D013403:Sugar Phosphates / Q000096:biosynthesis*
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D006360:Heat-Shock Proteins; D012274:Ribulosephosphates; D013403:Sugar Phosphates; C066494:3,4-dihydroxy-2-butanone-4-phosphate; C071147:ribB protein, E coli; C031524:ribulose 5-phosphate; D002238:Carbohydrate Epimerases; D019751:Intramolecular Transferases; C066493:L-3,4-dihydroxy-2-butanone-4-phosphate synthase; D012256:Riboflavin