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.


1qt4

From Proteopedia

(Difference between revisions)
Jump to: navigation, search
Line 1: Line 1:
-
[[Image:1qt4.jpg|left|200px]]<br /><applet load="1qt4" size="350" color="white" frame="true" align="right" spinBox="true"
+
[[Image:1qt4.jpg|left|200px]]
-
caption="1qt4, resolution 2.1&Aring;" />
+
 
-
'''T26Q MUTANT OF T4 LYSOZYME'''<br />
+
{{Structure
 +
|PDB= 1qt4 |SIZE=350|CAPTION= <scene name='initialview01'>1qt4</scene>, resolution 2.1&Aring;
 +
|SITE=
 +
|LIGAND= <scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene> and <scene name='pdbligand=BME:BETA-MERCAPTOETHANOL'>BME</scene>
 +
|ACTIVITY= [http://en.wikipedia.org/wiki/Lysozyme Lysozyme], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.17 3.2.1.17]
 +
|GENE=
 +
}}
 +
 
 +
'''T26Q MUTANT OF T4 LYSOZYME'''
 +
 
==Overview==
==Overview==
Line 7: Line 16:
==About this Structure==
==About this Structure==
-
1QT4 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacteriophage_t4 Bacteriophage t4] with <scene name='pdbligand=CL:'>CL</scene> and <scene name='pdbligand=BME:'>BME</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Lysozyme Lysozyme], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.17 3.2.1.17] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QT4 OCA].
+
1QT4 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Bacteriophage_t4 Bacteriophage t4]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QT4 OCA].
==Reference==
==Reference==
-
Structural basis of the conversion of T4 lysozyme into a transglycosidase by reengineering the active site., Kuroki R, Weaver LH, Matthews BW, Proc Natl Acad Sci U S A. 1999 Aug 3;96(16):8949-54. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=10430876 10430876]
+
Structural basis of the conversion of T4 lysozyme into a transglycosidase by reengineering the active site., Kuroki R, Weaver LH, Matthews BW, Proc Natl Acad Sci U S A. 1999 Aug 3;96(16):8949-54. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/10430876 10430876]
[[Category: Bacteriophage t4]]
[[Category: Bacteriophage t4]]
[[Category: Lysozyme]]
[[Category: Lysozyme]]
Line 21: Line 30:
[[Category: hydrolase]]
[[Category: hydrolase]]
-
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:43:33 2008''
+
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 13:42:21 2008''

Revision as of 11:42, 20 March 2008

Image:1qt4.jpg


PDB ID 1qt4

Drag the structure with the mouse to rotate
, resolution 2.1Å
Ligands: and
Activity: Lysozyme, with EC number 3.2.1.17
Coordinates: save as pdb, mmCIF, xml



T26Q MUTANT OF T4 LYSOZYME


Overview

In contrast to hen egg-white lysozyme, which retains the beta-configuration of the substrate in the product, T4 lysozyme (T4L) is an inverting glycosidase. The substitution Thr-26 --> His, however, converts T4L from an inverting to a retaining enzyme. It is shown here that the Thr-26 --> His mutant is also a transglycosidase. Indeed, the transglycosylation reaction can be more effective than hydrolysis. In contrast, wild-type T4L has no detectable transglycosidase activity. The results support the prior hypothesis that catalysis by the Thr-26 --> His mutant proceeds via a covalent intermediate. Further mutations (Glu-11 --> His, Asp-20 --> Cys) of the T26H mutant lysozyme indicate that the catalytic mechanism of this mutant requires Glu-11 as a general acid but Asp-20 is not essential. The results help provide an overall rationalization for the activity of glycosidases, in which a highly conserved acid group (Glu-11 in T4L, Glu-35 in hen egg-white lysozyme) on the beta-side of the substrate acts as a proton donor, whereas alterations in the placement and chemical identity of residues on the alpha-side of the substrate can lead to catalysis with or without retention of the configuration, to transglycosidase activity, or to the formation of a stable enzyme-substrate adduct.

About this Structure

1QT4 is a Single protein structure of sequence from Bacteriophage t4. Full crystallographic information is available from OCA.

Reference

Structural basis of the conversion of T4 lysozyme into a transglycosidase by reengineering the active site., Kuroki R, Weaver LH, Matthews BW, Proc Natl Acad Sci U S A. 1999 Aug 3;96(16):8949-54. PMID:10430876

Page seeded by OCA on Thu Mar 20 13:42:21 2008

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/1qt4"
Personal tools