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.


1ib6

From Proteopedia

(Difference between revisions)
Jump to: navigation, search
Line 1: Line 1:
-
[[Image:1ib6.jpg|left|200px]]
+
{{Seed}}
 +
[[Image:1ib6.png|left|200px]]
<!--
<!--
Line 9: Line 10:
{{STRUCTURE_1ib6| PDB=1ib6 | SCENE= }}
{{STRUCTURE_1ib6| PDB=1ib6 | SCENE= }}
-
'''CRYSTAL STRUCTURE OF R153C E. COLI MALATE DEHYDROGENASE'''
+
===CRYSTAL STRUCTURE OF R153C E. COLI MALATE DEHYDROGENASE===
-
==Overview==
+
<!--
-
Malate dehydrogenase specifically oxidizes malate to oxaloacetate. The specificity arises from three arginines in the active site pocket that coordinate the carboxyl groups of the substrate and stabilize the newly forming hydroxyl/keto group during catalysis. Here, the role of Arg-153 in distinguishing substrate specificity is examined by the mutant R153C. The x-ray structure of the NAD binary complex at 2.1 A reveals two sulfate ions bound in the closed form of the active site. The sulfate that occupies the substrate binding site has been translated approximately 2 A toward the opening of the active site cavity. Its new location suggests that the low catalytic turnover observed in the R153C mutant may be due to misalignment of the hydroxyl or ketone group of the substrate with the appropriate catalytic residues. In the NAD.pyruvate ternary complex, the monocarboxylic inhibitor is bound in the open conformation of the active site. The pyruvate is coordinated not by the active site arginines, but through weak hydrogen bonds to the amide backbone. Energy minimized molecular models of unnatural analogues of R153C (Wright, S. K., and Viola, R. E. (2001) J. Biol. Chem. 276, 31151-31155) reveal that the regenerated amino and amido side chains can form favorable hydrogen-bonding interactions with the substrate, although a return to native enzymatic activity is not observed. The low activity of the modified R153C enzymes suggests that precise positioning of the guanidino side chain is essential for optimal orientation of the substrate.
+
The line below this paragraph, {{ABSTRACT_PUBMED_11389141}}, adds the Publication Abstract to the page
 +
(as it appears on PubMed at http://www.pubmed.gov), where 11389141 is the PubMed ID number.
 +
-->
 +
{{ABSTRACT_PUBMED_11389141}}
==About this Structure==
==About this Structure==
Line 33: Line 37:
[[Category: Oxidoreductase]]
[[Category: Oxidoreductase]]
[[Category: Substrate specificity]]
[[Category: Substrate specificity]]
-
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 19:47:43 2008''
+
 
 +
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Tue Jul 1 10:41:55 2008''

Revision as of 07:41, 1 July 2008

Image:1ib6.png

Template:STRUCTURE 1ib6

CRYSTAL STRUCTURE OF R153C E. COLI MALATE DEHYDROGENASE

Template:ABSTRACT PUBMED 11389141

About this Structure

1IB6 is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.

Reference

Structural analyses of a malate dehydrogenase with a variable active site., Bell JK, Yennawar HP, Wright SK, Thompson JR, Viola RE, Banaszak LJ, J Biol Chem. 2001 Aug 17;276(33):31156-62. Epub 2001 Jun 1. PMID:11389141

Page seeded by OCA on Tue Jul 1 10:41:55 2008

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/1ib6"
Personal tools