1hjs: Difference between revisions

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Revision as of 12:38, 20 March 2008

File:1hjs.gif

, resolution 1.87Å

Sites:

Ligands:

, , and

Activity:

Arabinogalactan endo-1,4-beta-galactosidase, with EC number 3.2.1.89

Coordinates:

save as pdb, mmCIF, xml

STRUCTURE OF TWO FUNGAL BETA-1,4-GALACTANASES: SEARCHING FOR THE BASIS FOR TEMPERATURE AND PH OPTIMUM.

OverviewOverview

beta-1,4-Galactanases hydrolyze the galactan side chains that are part of the complex carbohydrate structure of the pectin. They are assigned to family 53 of the glycoside hydrolases and display significant variations in their pH and temperature optimum and stability. Two fungal beta-1,4-galactanases from Myceliophthora thermophila and Humicola insolens have been cloned and heterologously expressed, and the crystal structures of the gene products were determined. The structures are compared to the previously only known family 53 structure of the galactanase from Aspergillus aculeatus (AAGAL) showing approximately 56% identity. The M. thermophila and H. insolens galactanases are thermophilic enzymes and are most active at neutral to basic pH, whereas AAGAL is mesophilic and most active at acidic pH. The structure of the M. thermophila galactanase (MTGAL) was determined from crystals obtained with HEPES and TRIS buffers to 1.88 A and 2.14 A resolution, respectively. The structure of the H. insolens galactanase (HIGAL) was determined to 2.55 A resolution. The thermostability of MTGAL and HIGAL correlates with increase in the protein rigidity and electrostatic interactions, stabilization of the alpha-helices, and a tighter packing. An inspection of the active sites in the three enzymes identifies several amino acid substitutions that could explain the variation in pH optimum. Examination of the activity as a function of pH for the D182N mutant of AAGAL and the A90S/ H91D mutant of MTGAL showed that the difference in pH optimum between AAGAL and MTGAL is at least partially associated with differences in the nature of residues at positions 182, 90, and/or 91.

About this StructureAbout this Structure

1HJS is a Single protein structure of sequence from Corynascus heterothallicus. Full crystallographic information is available from OCA.

ReferenceReference

Structure of two fungal beta-1,4-galactanases: searching for the basis for temperature and pH optimum., Le Nours J, Ryttersgaard C, Lo Leggio L, Ostergaard PR, Borchert TV, Christensen LL, Larsen S, Protein Sci. 2003 Jun;12(6):1195-204. PMID:12761390

Page seeded by OCA on Thu Mar 20 11:37:57 2008

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OCA

@@ Line 1: / Line 1: @@
-[[Image:1hjs.gif|left|200px]]<br /><applet load="1hjs" size="350" color="white" frame="true" align="right" spinBox="true"
+[[Image:1hjs.gif|left|200px]]
-caption="1hjs, resolution 1.87&Aring;" />
-'''STRUCTURE OF TWO FUNGAL BETA-1,4-GALACTANASES: SEARCHING FOR THE BASIS FOR TEMPERATURE AND PH OPTIMUM.'''<br />
+ {{Structure
+|PDB= 1hjs |SIZE=350|CAPTION= <scene name='initialview01'>1hjs</scene>, resolution 1.87&Aring;
+|SITE= <scene name='pdbsite=AC1:Peg+Binding+Site+For+Chain+D'>AC1</scene>
+|LIGAND= <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene>, <scene name='pdbligand=EPE:4-(2-HYDROXYETHYL)-1-PIPERAZINE+ETHANESULFONIC+ACID'>EPE</scene> and <scene name='pdbligand=PEG:DI(HYDROXYETHYL)ETHER'>PEG</scene>
+|ACTIVITY= [http://en.wikipedia.org/wiki/Arabinogalactan_endo-1,4-beta-galactosidase Arabinogalactan endo-1,4-beta-galactosidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.89 3.2.1.89]
+|GENE=
+}}
+'''STRUCTURE OF TWO FUNGAL BETA-1,4-GALACTANASES: SEARCHING FOR THE BASIS FOR TEMPERATURE AND PH OPTIMUM.'''
 ==Overview==
@@ Line 7: / Line 16: @@
 ==About this Structure==
-HJS is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Corynascus_heterothallicus Corynascus heterothallicus] with <scene name='pdbligand=NAG:'>NAG</scene>, <scene name='pdbligand=SO4:'>SO4</scene>, <scene name='pdbligand=EPE:'>EPE</scene> and <scene name='pdbligand=PEG:'>PEG</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Arabinogalactan_endo-1,4-beta-galactosidase Arabinogalactan endo-1,4-beta-galactosidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.89 3.2.1.89] Known structural/functional Site: <scene name='pdbsite=AC1:Peg+Binding+Site+For+Chain+D'>AC1</scene>. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1HJS OCA].
+HJS is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Corynascus_heterothallicus Corynascus heterothallicus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1HJS OCA].
 ==Reference==
-Structure of two fungal beta-1,4-galactanases: searching for the basis for temperature and pH optimum., Le Nours J, Ryttersgaard C, Lo Leggio L, Ostergaard PR, Borchert TV, Christensen LL, Larsen S, Protein Sci. 2003 Jun;12(6):1195-204. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=12761390 12761390]
+Structure of two fungal beta-1,4-galactanases: searching for the basis for temperature and pH optimum., Le Nours J, Ryttersgaard C, Lo Leggio L, Ostergaard PR, Borchert TV, Christensen LL, Larsen S, Protein Sci. 2003 Jun;12(6):1195-204. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/12761390 12761390]
 [[Category: Arabinogalactan endo-1,4-beta-galactosidase]]
 [[Category: Corynascus heterothallicus]]
@@ Line 25: / Line 34: @@
 [[Category: PEG]]
 [[Category: SO4]]
-[[Category: 4-galactanases]]
+[[Category: 4-galactanase]]
 [[Category: alkalophile]]
 [[Category: beta-1]]
@@ Line 35: / Line 44: @@
 [[Category: thermostability]]
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:01:57 2008''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 11:37:57 2008''