Purification and characterization of UDP-glucose:tetrahydrobiopterin glucosyltransferase from Synechococcus sp. PCC 7942.
Tetrahydrobiopterin (BH4)-glucoside was identified from Synechococcus sp. PCC 7942 by HPLC analysis and the enzymatic activity of a glycosyltransferase producing the compound from UDP-glucose and BH4. The novel enzyme, named UDP-glucose:BH4 glucosyltransferase, has been purified 846-fold from the cytosolic fraction of Synechococcus sp. PCC 7942 to apparent homogeneity on SDS-PAGE. The native enzyme exists as a monomer having a molecular mass of 39.2 kDa on SDS-PAGE. The enzyme was active over a broad range of pH from 6.5 to 10.5 but most active at pH 10.0. The enzyme required Mn(2+) for maximal activity. Optimum temperature was 42 degrees C. Apparent K(m) values for BH4 and UDP-glucose were determined as 4.3 microM and 188 microM, respectively, and V(max) values were 16.1 and 15.1 pmol min(-1) mg(-1), respectively. The N-terminal amino acid sequence was Thr-Ala-His-Arg-Phe-Lys-Phe-Val-Ser-Thr-Pro-Val-Gly-, sharing high homology with the predicted N-terminal sequence of an unidentified open reading frame slr1166 determined in the genome of Synechocystis sp. PCC 6803, which is known to produce a pteridine glycoside cyanopterin.
Chung
H J
HJ
Department of Microbiology, Inje University, 621-749, Kimhae, South Korea.
Kim
Y A
YA
Kim
Y J
YJ
Choi
Y K
YK
Hwang
Y K
YK
Park
Y S
YS
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000302:isolation & purification; D001708:Biopterins / Q000031:analogs & derivatives* / Q000737:chemistry; D000458:Cyanobacteria / Q000201:enzymology / Q000378:metabolism*; D005960:Glucosides / Q000032:analysis; D005964:Glucosyltransferases / Q000737:chemistry* / Q000302:isolation & purification; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008670:Metals; D008969:Molecular Sequence Data; D013379:Substrate Specificity; D013696:Temperature; D014532:Uridine Diphosphate Glucose / Q000737:chemistry
D001426:Bacterial Proteins; D005960:Glucosides; D008670:Metals; D001708:Biopterins; D005964:Glucosyltransferases; C003402:sapropterin; D014532:Uridine Diphosphate Glucose