Crystal structures of RbsD leading to the identification of cytoplasmic sugar-binding proteins with a novel folding architecture

Min Sung Kim, Joon Shin, Weontae Lee, Heung Soo Lee, Byung Ha Oh

Research output: Contribution to journalArticle

18 Citations (Scopus)


RbsD is the only protein whose biochemical function is unknown among the six gene products of the rbs operon involved in the active transport of ribose. FucU, a paralogue of RbsD conserved from bacteria to human, is also the only protein whose function is unknown among the seven gene products of the L-fucose regulon. Here we report the crystal structures of Bacillus subtilis RbsD, which reveals a novel decameric toroidal assembly of the protein. Nuclear magnetic resonance and other studies on RbsD reveal that the intersubunit cleft of the protein binds specific forms of D-ribose, but it does not have an enzyme activity toward the sugar. Likewise, FucU binds L-fucose but lacks an enzyme activity toward this sugar. We conclude that RbsD and FucU are cytoplasmic sugar-binding proteins, a novel class of proteins whose functional role may lie in helping influx of the sugar substrates.

Original languageEnglish
Pages (from-to)28173-28180
Number of pages8
JournalJournal of Biological Chemistry
Issue number30
Publication statusPublished - 2003 Jul 25


All Science Journal Classification (ASJC) codes

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Cite this