1l7k
From Proteopedia
| Line 1: | Line 1: | ||
[[Image:1l7k.gif|left|200px]] | [[Image:1l7k.gif|left|200px]] | ||
| - | + | <!-- | |
| - | + | The line below this paragraph, containing "STRUCTURE_1l7k", creates the "Structure Box" on the page. | |
| - | + | You may change the PDB parameter (which sets the PDB file loaded into the applet) | |
| - | + | or the SCENE parameter (which sets the initial scene displayed when the page is loaded), | |
| - | + | or leave the SCENE parameter empty for the default display. | |
| - | | | + | --> |
| - | | | + | {{STRUCTURE_1l7k| PDB=1l7k | SCENE= }} |
| - | + | ||
| - | + | ||
| - | }} | + | |
'''x-ray structure of galactose mutarotase from Lactococcus lactis complexed with galactose''' | '''x-ray structure of galactose mutarotase from Lactococcus lactis complexed with galactose''' | ||
| Line 28: | Line 25: | ||
[[Category: Holden, H M.]] | [[Category: Holden, H M.]] | ||
[[Category: Thoden, J B.]] | [[Category: Thoden, J B.]] | ||
| - | [[Category: | + | [[Category: Epimerase]] |
| - | [[Category: | + | [[Category: Galactose metabolism]] |
| - | [[Category: | + | [[Category: Mutarotase]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 23:37:58 2008'' | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 20:38, 2 May 2008
x-ray structure of galactose mutarotase from Lactococcus lactis complexed with galactose
Overview
Galactose mutarotase plays a key role in normal galactose metabolism by catalyzing the interconversion of beta-D-galactose and alpha-D-galactose. Here we describe the three-dimensional architecture of galactose mutarotase from Lactococcus lactis determined to 1.9-A resolution. Each subunit of the dimeric enzyme displays a distinctive beta-sandwich motif. This tertiary structural element was first identified in beta-galactosidase and subsequently observed in copper amine oxidase, hyaluronate lyase, chondroitinase, and maltose phosphorylase. Two cis-peptides are found in each subunit, namely Pro(67) and Lys(136). The active site is positioned in a rather open cleft, and the electron density corresponding to the bound galactose unequivocally demonstrates that both anomers of the substrate are present in the crystalline enzyme. Those residues responsible for anchoring the sugar to the protein include Arg(71), His(96), His(170), Asp(243), and Glu(304). Both His(96) and His(170) are strictly conserved among mutarotase amino acid sequences determined thus far. The imidazole nitrogens of these residues are located within hydrogen bonding distance to the C-5 oxygen of galactose. Strikingly, the carboxylate group of Glu(304) is situated at approximately 2.7 A from the 1'-hydroxyl group of galactose, thereby suggesting its possible role as a general acid/base group.
About this Structure
1L7K is a Single protein structure of sequence from Lactococcus lactis. Full crystallographic information is available from OCA.
Reference
High resolution X-ray structure of galactose mutarotase from Lactococcus lactis., Thoden JB, Holden HM, J Biol Chem. 2002 Jun 7;277(23):20854-61. Epub 2002 Mar 20. PMID:11907040 Page seeded by OCA on Fri May 2 23:37:58 2008
