This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.

Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.


1cgx

From Proteopedia

(Difference between revisions)
Jump to: navigation, search
(New page: 200px<br /><applet load="1cgx" size="450" color="white" frame="true" align="right" spinBox="true" caption="1cgx, resolution 2.5&Aring;" /> '''SITE DIRECTED MUTATIO...)
Current revision (15:40, 13 March 2024) (edit) (undo)
 
(14 intermediate revisions not shown.)
Line 1: Line 1:
-
[[Image:1cgx.jpg|left|200px]]<br /><applet load="1cgx" size="450" color="white" frame="true" align="right" spinBox="true"
 
-
caption="1cgx, resolution 2.5&Aring;" />
 
-
'''SITE DIRECTED MUTATIONS OF THE ACTIVE SITE RESIDUE TYROSINE 195 OF CYCLODEXTRIN GLYXOSYLTRANSFERASE FROM BACILLUS CIRCULANS STRAIN 251 AFFECTING ACTIVITY AND PRODUCT SPECIFICITY'''<br />
 
-
==Overview==
+
==SITE DIRECTED MUTATIONS OF THE ACTIVE SITE RESIDUE TYROSINE 195 OF CYCLODEXTRIN GLYXOSYLTRANSFERASE FROM BACILLUS CIRCULANS STRAIN 251 AFFECTING ACTIVITY AND PRODUCT SPECIFICITY==
-
Tyrosine 195 is located in the center of the active site cleft of, cyclodextrin glycosyltransferase (EC 2.4.1.19) from Bacillus circulans, strain 251. Alignment of amino acid sequences of CGTases and, alpha-amylases, and the analysis of the binding mode of the substrate, analogue acarbose in the active site cleft [Strokopytov, B., et al. (1995), Biochemistry 34, (in press)], suggested that Tyr195 plays an important, role in cyclization of oligosaccharides. Tyr195 therefore was replaced, with Phe (Y195F), Trp (Y195W), Leu (Y195L), and Gly (Y195G). Mutant, proteins were purified and crystallized, and their X-ray structures were, determined at 2.5-2.6 angstrum resolution, allowing a detailed comparison, of their biochemical properties and three-dimensional structures with, those of the wild-type CGTase protein. The mutant proteins possessed, significantly reduced cyclodextrin forming and coupling activities but, were not negatively affected in the disproportionation and saccharifying, reactions. Also under production process conditions, after a 45 h, incubation with a 10% starch solution, the Y195W, Y195L, and Y195G mutants, showed a lower overall conversion of starch into cyclodextrins. These, mutants produced a considerable amount of linear maltooligosaccharides., The presence of aromatic amino acids (Tyr or Phe) at the Tyr195 position, thus appears to be of crucial importance for an efficient cyclization, reaction, virtually preventing the formation of linear products. Mass, spectrometry of the Y195L reaction mixture, but not that of the other, mutants and the wild type, revealed a shift toward the synthesis (in low, yields) of larger products, especially of beta- and gamma- (but no alpha-), cyclodextrins and minor amounts of delta-, epsilon-, zeta- and, eta-cyclodextrins.(ABSTRACT TRUNCATED AT 250 WORDS)
+
<StructureSection load='1cgx' size='340' side='right'caption='[[1cgx]], [[Resolution|resolution]] 2.50&Aring;' scene=''>
-
 
+
== Structural highlights ==
-
==About this Structure==
+
<table><tr><td colspan='2'>[[1cgx]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Niallia_circulans Niallia circulans]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1CGX OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1CGX FirstGlance]. <br>
-
1CGX is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_circulans Bacillus circulans] with MAL and CA as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Cyclomaltodextrin_glucanotransferase Cyclomaltodextrin glucanotransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.4.1.19 2.4.1.19] Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1CGX OCA].
+
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.5&#8491;</td></tr>
-
 
+
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=GLC:ALPHA-D-GLUCOSE'>GLC</scene>, <scene name='pdbligand=PRD_900001:alpha-maltose'>PRD_900001</scene></td></tr>
-
==Reference==
+
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1cgx FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1cgx OCA], [https://pdbe.org/1cgx PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1cgx RCSB], [https://www.ebi.ac.uk/pdbsum/1cgx PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1cgx ProSAT]</span></td></tr>
-
Site-directed mutations in tyrosine 195 of cyclodextrin glycosyltransferase from Bacillus circulans strain 251 affect activity and product specificity., Penninga D, Strokopytov B, Rozeboom HJ, Lawson CL, Dijkstra BW, Bergsma J, Dijkhuizen L, Biochemistry. 1995 Mar 14;34(10):3368-76. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=7880832 7880832]
+
</table>
-
[[Category: Bacillus circulans]]
+
== Function ==
-
[[Category: Cyclomaltodextrin glucanotransferase]]
+
[https://www.uniprot.org/uniprot/CDGT2_NIACI CDGT2_NIACI]
-
[[Category: Single protein]]
+
== Evolutionary Conservation ==
-
[[Category: Dijkstra, B.W.]]
+
[[Image:Consurf_key_small.gif|200px|right]]
-
[[Category: Strokopytov, B.V.]]
+
Check<jmol>
-
[[Category: CA]]
+
<jmolCheckbox>
-
[[Category: MAL]]
+
<scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/cg/1cgx_consurf.spt"</scriptWhenChecked>
-
[[Category: glycosyltransferase]]
+
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
-
 
+
<text>to colour the structure by Evolutionary Conservation</text>
-
''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 12:26:31 2007''
+
</jmolCheckbox>
 +
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1cgx ConSurf].
 +
<div style="clear:both"></div>
 +
__TOC__
 +
</StructureSection>
 +
[[Category: Large Structures]]
 +
[[Category: Niallia circulans]]
 +
[[Category: Dijkstra BW]]
 +
[[Category: Strokopytov BV]]

Current revision

SITE DIRECTED MUTATIONS OF THE ACTIVE SITE RESIDUE TYROSINE 195 OF CYCLODEXTRIN GLYXOSYLTRANSFERASE FROM BACILLUS CIRCULANS STRAIN 251 AFFECTING ACTIVITY AND PRODUCT SPECIFICITY

PDB ID 1cgx

Drag the structure with the mouse to rotate

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/1cgx"
Personal tools