1Z45

Crystal structure of the gal10 fusion protein galactose mutarotase/UDP-galactose 4-epimerase from Saccharomyces cerevisiae complexed with NAD, UDP-glucose, and galactose

1Z45 の概要

• エントリーDOI: 10.2210/pdb1z45/pdb
• 分子名称: GAL10 bifunctional protein, beta-D-galactopyranose, SODIUM ION, ... (6 entities in total)
• 機能のキーワード: epimerase, mutarotase, metabolism, isomerase
• 由来する生物種: Saccharomyces cerevisiae (baker's yeast)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 79717.81

構造登録者

Thoden, J.B.,Holden, H.M. (登録日: 2005-03-15, 公開日: 2005-04-05, 最終更新日: 2023-08-23)

主引用文献

Thoden, J.B.,Holden, H.M.
The molecular architecture of galactose mutarotase/UDP-galactose 4-epimerase from Saccharomyces cerevisiae.
J.Biol.Chem., 280:21900-21907, 2005

PubMed Abstract: The metabolic pathway by which beta-D-galactose is converted to glucose 1-phosphate is known as the Leloir pathway and consists of four enzymes. In most organisms, these enzymes appear to exist as soluble entities in the cytoplasm. In yeast such as Saccharomyces cerevisiae, however, the first and last enzymes of the pathway, galactose mutarotase and UDP-galactose 4-epimerase, are contained within a single polypeptide chain referred to as Gal10p. Here we report the three-dimensional structure of Gal10p in complex with NAD(+), UDP-glucose, and beta-D-galactose determined to 1.85-A resolution. The enzyme is dimeric with dimensions of approximately 91 A x 135 A x 108 A and assumes an almost V-shaped appearance. The overall architecture of the individual subunits can be described in terms of two separate N- and C-terminal domains connected by a Type II turn formed by Leu-357 to Val-360. The first 356 residues of Gal10p fold into the classical bilobal topology observed for all other UDP-galactose 4-epimerases studied thus far. This N-terminal domain contains the binding sites for NAD(+) and UDP-glucose. The polypeptide chain extending from Glu-361 to Ser-699 adopts a beta-sandwich motif and harbors the binding site for beta-D-galactose. The two active sites of Gal10p are separated by over 50 A. This investigation represents the first structural analysis of a dual function enzyme in the Leloir pathway.

PubMed: 15795221
DOI: 10.1074/jbc.M502411200

実験手法

X-RAY DIFFRACTION (1.85 Å)