1X8D

Crystal structure of E. coli YiiL protein containing L-rhamnose

Summary for 1X8D

• Entry DOI: 10.2210/pdb1x8d/pdb
• Descriptor: Hypothetical protein yiiL, L-RHAMNOSE (3 entities in total)
• Functional Keywords: mutarotase, l-rhamnose, biosynthetic protein
• Biological source: Escherichia coli
• Total number of polymer chains: 4
• Total formula weight: 49772.08

Authors

Ryu, K.S.,Kim, J.I.,Cho, S.J.,Park, D.,Park, C.,Lee, J.O.,Choi, B.S. (deposition date: 2004-08-18, release date: 2005-05-17, Last modification date: 2024-03-13)

Primary citation

Ryu, K.S.,Kim, J.I.,Cho, S.J.,Park, D.,Park, C.,Cheong, H.K.,Lee, J.O.,Choi, B.S.
Structural Insights into the Monosaccharide Specificity of Escherichia coli Rhamnose Mutarotase
J.Mol.Biol., 349:153-162, 2005

PubMed Abstract: 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.

PubMed: 15876375
DOI: 10.1016/j.jmb.2005.03.047

Experimental method

X-RAY DIFFRACTION (1.8 Å)