From Proteopedia
(Difference between revisions)
proteopedia linkproteopedia link
|
|
| Line 1: |
Line 1: |
| - | [[Image:2e22.jpg|left|200px]] | + | {{Seed}} |
| | + | [[Image:2e22.png|left|200px]] |
| | | | |
| | <!-- | | <!-- |
| Line 9: |
Line 10: |
| | {{STRUCTURE_2e22| PDB=2e22 | SCENE= }} | | {{STRUCTURE_2e22| PDB=2e22 | SCENE= }} |
| | | | |
| - | '''Crystal structure of xanthan lyase in complex with mannose'''
| + | ===Crystal structure of xanthan lyase in complex with mannose=== |
| | | | |
| | | | |
| - | ==Overview==
| + | <!-- |
| - | Xanthan is a bacterial heteropolysaccharide composed of pentasaccharide repeating units, i.e., a cellobiose as a backbone and a trisaccharide consisting of two mannoses and one glucuronic acid as a side chain. Nonreducing terminal mannose residues of xanthan side chains are partially pyruvated. Bacillus sp. GL1 xanthan lyase, a member of polysaccharide lyase family 8, acts specifically on pyruvated side chains of xanthan and yields pyruvated mannose through a beta-elimination reaction by using a single Tyr255 residue as base and acid catalysts. Here we show structural factors for substrate recognition by xanthan lyase through X-ray crystallographic and mutational analyses. The enzyme accommodates mannose and pyruvated mannose at the -1 subsite, although both inhibitor and dissociation constants of the two monosaccharides indicated that the affinity of pyruvated mannose for xanthan lyase is much higher than that of mannose. The high affinity of pyruvated mannose is probably due to the formation of additional hydrogen bonds between the carboxyl group of pyruvated mannose and amino acid residues of Tyr315 and Arg612. Site-directed mutagenesis of the two residues demonstrated that Arg612 is a key residue in recognizing pyruvated mannose. Arg612 is located in the protruding loop covering the substrate, suggesting that the loop functions as a lid that is responsible for the proper accommodation of the substrate at the active site.
| + | The line below this paragraph, {{ABSTRACT_PUBMED_17223699}}, adds the Publication Abstract to the page |
| | + | (as it appears on PubMed at http://www.pubmed.gov), where 17223699 is the PubMed ID number. |
| | + | --> |
| | + | {{ABSTRACT_PUBMED_17223699}} |
| | | | |
| | ==About this Structure== | | ==About this Structure== |
| Line 30: |
Line 34: |
| | [[Category: Polysaccharide lyase]] | | [[Category: Polysaccharide lyase]] |
| | [[Category: Xanthan]] | | [[Category: Xanthan]] |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun May 4 01:46:45 2008'' | + | |
| | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat Jul 5 16:22:59 2008'' |
Revision as of 13:22, 5 July 2008
Template:STRUCTURE 2e22
Crystal structure of xanthan lyase in complex with mannose
Template:ABSTRACT PUBMED 17223699
About this Structure
2E22 is a Single protein structure of sequence from Bacillus sp.. Full crystallographic information is available from OCA.
Reference
A structural factor responsible for substrate recognition by Bacillus sp. GL1 xanthan lyase that acts specifically on pyruvated side chains of xanthan., Maruyama Y, Mikami B, Hashimoto W, Murata K, Biochemistry. 2007 Jan 23;46(3):781-91. PMID:17223699
Page seeded by OCA on Sat Jul 5 16:22:59 2008
