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.


1n2t

From Proteopedia

(Difference between revisions)
Jump to: navigation, search
Line 1: Line 1:
-
[[Image:1n2t.jpg|left|200px]]
+
{{Seed}}
 +
[[Image:1n2t.png|left|200px]]
<!--
<!--
Line 9: Line 10:
{{STRUCTURE_1n2t| PDB=1n2t | SCENE= }}
{{STRUCTURE_1n2t| PDB=1n2t | SCENE= }}
-
'''C-DES Mutant K223A with GLY Covalenty Linked to the PLP-cofactor'''
+
===C-DES Mutant K223A with GLY Covalenty Linked to the PLP-cofactor===
-
==Overview==
+
<!--
-
The cystine lyase (C-DES) of Synechocystis is a pyridoxal-5'-phosphate-dependent enzyme distantly related to the family of NifS-like proteins. The crystal structure of an N-terminal modified variant has recently been determined. Herein, the reactivity of this enzyme variant was investigated spectroscopically in solution and in the crystalline state to follow the course of the reaction and to determine the catalytic mechanism on a molecular level. Using the stopped-flow technique, the reaction with the preferred substrate cystine was found to follow biphasic kinetics leading to the formation of absorbing species at 338 and 470 nm, attributed to the external aldimine and the alpha-aminoacrylate; the reaction with cysteine also exhibited biphasic behavior but only the external aldimine accumulated. The same reaction intermediates were formed in crystals as seen by polarized absorption microspectrophotometry, thus indicating that C-DES is catalytically competent in the crystalline state. The three-dimensional structure of the catalytically inactive mutant C-DES(K223A) in the presence of cystine showed the formation of an external aldimine species, in which two alternate conformations of the substrate were observed. The combined results allow a catalytic mechanism to be proposed involving interactions between cystine and the active site residues Arg-360, Arg-369, and Trp-251*; these residues reorient during the beta-elimination reaction, leading to the formation of a hydrophobic pocket that stabilizes the enolimine tautomer of the aminoacrylate and the cysteine persulfide product.
+
The line below this paragraph, {{ABSTRACT_PUBMED_12386155}}, adds the Publication Abstract to the page
 +
(as it appears on PubMed at http://www.pubmed.gov), where 12386155 is the PubMed ID number.
 +
-->
 +
{{ABSTRACT_PUBMED_12386155}}
==About this Structure==
==About this Structure==
Line 33: Line 37:
[[Category: Nif]]
[[Category: Nif]]
[[Category: Pyridoxal 5'-phosphate]]
[[Category: Pyridoxal 5'-phosphate]]
-
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 02:01:07 2008''
+
 
 +
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Jul 27 18:53:47 2008''

Revision as of 15:53, 27 July 2008

Image:1n2t.png

Template:STRUCTURE 1n2t

C-DES Mutant K223A with GLY Covalenty Linked to the PLP-cofactor

Template:ABSTRACT PUBMED 12386155

About this Structure

1N2T is a Single protein structure of sequence from Synechocystis sp. pcc 6714. Full crystallographic information is available from OCA.

Reference

Snapshots of the cystine lyase C-DES during catalysis. Studies in solution and in the crystalline state., Kaiser JT, Bruno S, Clausen T, Huber R, Schiaretti F, Mozzarelli A, Kessler D, J Biol Chem. 2003 Jan 3;278(1):357-65. Epub 2002 Oct 16. PMID:12386155

Page seeded by OCA on Sun Jul 27 18:53:47 2008

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/1n2t"
Personal tools