Publications

• NMR application probes a novel and ubiquitous family of enzymes that alter monosaccharide configuration.

  Ryu K.-S., Kim C., Kim I., Yoo S., Choi B.-S., Park C.

  By exploiting nuclear magnetic resonance (NMR) techniques along with novel applications of saturation difference analysis, we deciphered the functions of the previously uncharacterized products of three bacterial genes, rbsD, fucU, and yiiL, which are part of the ribose, fucose, and rhamnose opero ... >> More

  By exploiting nuclear magnetic resonance (NMR) techniques along with novel applications of saturation difference analysis, we deciphered the functions of the previously uncharacterized products of three bacterial genes, rbsD, fucU, and yiiL, which are part of the ribose, fucose, and rhamnose operons of Escherichia coli, respectively. We show that RbsD catalyzes the pyran to furan conversion of ribose, whereas FucU and YiiL are involved in the catalysis of the anomeric conversion of their respective sugars. It was observed that the anomeric exchange of only ribofuranose, not ribopyranose, occurs spontaneously in solution rationalizing its evolutionary incorporation into the nucleic acid. The RbsD and FucU proteins share sequence homology and belong to the same protein family that is found from eubacteria to human, whereas the YiiL homologues exist in archaebacteria and lower eukaryotes. These enzymes, including the galactose mutarotase, exhibit a certain degree of cross-specificity to structurally analogous sugars thereby encompassing all existing monosaccharides in terms of their reactivities. The ubiquitous presence of enzymes involved in the anomeric changes of monosaccharides highlights an importance of these activities in various cellular processes requiring efficient monosaccharide utilization. << Less

  J. Biol. Chem. 279:25544-25548(2004) [PubMed] [EuropePMC]

  This publication is cited by 3 other entries.

• Structural insights into the monosaccharide specificity of Escherichia coli rhamnose mutarotase.

  Ryu K.-S., Kim J.-I., Cho S.-J., Park D., Park C., Cheong H.-K., Lee J.-O., Choi B.-S.

  The crystal structure of Escherichia coli rhamnose mutarotase (YiiL) is completely different from the previously reported structures of the Lactococcus lactis galactose mutarotase and the Bacillus subtilis RbsD (pyranase). YiiL exists as a locally asymmetric dimer, which is stabilized by an interm ... >> More

  The crystal structure of Escherichia coli rhamnose mutarotase (YiiL) is completely different from the previously reported structures of the Lactococcus lactis galactose mutarotase and the Bacillus subtilis RbsD (pyranase). YiiL exists as a locally asymmetric dimer, which is stabilized by an intermolecular beta-sheet, various hydrophobic interactions, and a cation-pi interaction with a salt-bridge. The protein folds of YiiL are similar to those of a Streptomyces coelicolor mono-oxygenase and a hypothetical Arabidopsis thaliana protein At3g17210. By assaying the enzymatic activity of six active-site mutants and by comparing the crystal structure-derived active site conformations of YiiL, RbsD, and a galactose mutarotase, we were able to define the amino acid residues required for catalysis and suggest a possible catalytic mechanism for YiiL. Although the active-site amino acid residues of YiiL (His, Tyr, and Trp) differ greatly from those of galactose mutarotase (His, Glu, and Asp), their geometries, which determine the structures of the preferred monosaccharide substrates, are conserved. In addition, the in vivo function of YiiL was assessed by constructing a mutant E.coli strain that carries a yiiL deletion. The presence of the yiiL gene is critical for efficient cell growth only when concentrations of l-rhamnose are limited. << Less

  J. Mol. Biol. 349:153-162(2005) [PubMed] [EuropePMC]