2CIQ

Structure-based functional annotation: Yeast ymr099c codes for a D- hexose-6-phosphate mutarotase.

Summary for 2CIQ

• Entry DOI: 10.2210/pdb2ciq/pdb
• Related: 2CIR 2CIS
• Descriptor: HEXOSE-6-PHOSPHATE MUTAROTASE, 4-(2-HYDROXYETHYL)-1-PIPERAZINE ETHANESULFONIC ACID, SODIUM ION, ... (6 entities in total)
• Functional Keywords: epimerase, isomerase, mannose-6-phosphate-1-epimerase, galactose-6-phosphate-1-epimerase, d-hexose-6-phosphate-1-mutarotase
• Biological source: Saccharomyces cerevisiae (BAKER'S YEAST)
• Total number of polymer chains: 1
• Total formula weight: 34541.29

Authors

Graille, M.,Baltaze, J.-P.,Leulliot, N.,Liger, D.,Quevillon-Cheruel, S.,van Tilbeurgh, H. (deposition date: 2006-03-24, release date: 2006-07-11, Last modification date: 2023-12-13)

Primary citation

Graille, M.,Baltaze, J.P.,Leulliot, N.,Liger, D.,Quevillon-Cheruel, S.,van Tilbeurgh, H.
Structure-based functional annotation: yeast ymr099c codes for a D-hexose-6-phosphate mutarotase.
J. Biol. Chem., 281:30175-30185, 2006

PubMed Abstract: Despite the generation of a large amount of sequence information over the last decade, more than 40% of well characterized enzymatic functions still lack associated protein sequences. Assigning protein sequences to documented biochemical functions is an interesting challenge. We illustrate here that structural genomics may be a reasonable approach in addressing these questions. We present the crystal structure of the Saccharomyces cerevisiae YMR099cp, a protein of unknown function. YMR099cp adopts the same fold as galactose mutarotase and shares the same catalytic machinery necessary for the interconversion of the alpha and beta anomers of galactose. The structure revealed the presence in the active site of a sulfate ion attached by an arginine clamp made by the side chain from two strictly conserved arginine residues. This sulfate is ideally positioned to mimic the phosphate group of hexose 6-phosphate. We have subsequently successfully demonstrated that YMR099cp is a hexose-6-phosphate mutarotase with broad substrate specificity. We solved high resolution structures of some substrate enzyme complexes, further confirming our functional hypothesis. The metabolic role of a hexose-6-phosphate mutarotase is discussed. This work illustrates that structural information has been crucial to assign YMR099cp to the orphan EC activity: hexose-phosphate mutarotase.

PubMed: 16857670
DOI: 10.1074/jbc.M604443200

Experimental method

X-RAY DIFFRACTION (1.7 Å)