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.


1nuj

From Proteopedia

(Difference between revisions)
Jump to: navigation, search
Line 1: Line 1:
-
[[Image:1nuj.gif|left|200px]]
+
{{Seed}}
 +
[[Image:1nuj.png|left|200px]]
<!--
<!--
Line 9: Line 10:
{{STRUCTURE_1nuj| PDB=1nuj | SCENE= }}
{{STRUCTURE_1nuj| PDB=1nuj | SCENE= }}
-
'''THE LEADZYME STRUCTURE BOUND TO MG(H20)6(II) AT 1.8 A RESOLUTION'''
+
===THE LEADZYME STRUCTURE BOUND TO MG(H20)6(II) AT 1.8 A RESOLUTION===
-
==Overview==
+
<!--
-
The leadzyme is a small ribozyme, derived from in vitro selection, which catalyzes site specific, Pb(2+)-dependent RNA cleavage. Pb(2+) is required for activity; Mg(2+) inhibits activity, while many divalent and trivalent ions enhance it. The leadzyme structure consists of an RNA duplex interrupted by a trinucleotide bulge. Here, crystal structures determined to 1.8 A resolution, both with Mg(2+) as the sole divalent counterion and with Mg(2+) and Sr(2+) (which mimics Pb(2+) with respect to binding but not catalysis), reveal the metal ion interactions with both the ground state and precatalytic conformations of the leadzyme. Mg(H(2)O)(6)(2+) ions bridge complementary strands of the duplex at multiple locations by binding tandem purines of one RNA strand in the major groove. At one site, Mg(H(2)O)(6)(2+) ligates the phosphodiester backbone of the trinucleotide bulge in the ground state conformation, but not in the precatalytic conformation, suggesting (a) Mg(2+) may inhibit leadzyme activity by stabilizing the ground state and (b) metal ions which displace Mg(2+) from this site may activate the leadzyme. Binding of Sr(2+) to the presumed catalytic Pb(2+) site in the precatalytic leadzyme induces local structural changes in a manner that would facilitate alignment of the catalytic ribose 2'-hydroxyl with the scissile bond for cleavage. These data support a model wherein binding of a catalytic ion to a precatalytic conformation of the leadzyme, in conjunction with the flexibility of the trinucleotide bulge, may facilitate structural rearrangements around the scissle phosphodiester bond favoring configurations that allow bond cleavage.
+
The line below this paragraph, {{ABSTRACT_PUBMED_12911297}}, adds the Publication Abstract to the page
 +
(as it appears on PubMed at http://www.pubmed.gov), where 12911297 is the PubMed ID number.
 +
-->
 +
{{ABSTRACT_PUBMED_12911297}}
==About this Structure==
==About this Structure==
Line 32: Line 36:
[[Category: Rna]]
[[Category: Rna]]
[[Category: Sticky end]]
[[Category: Sticky end]]
-
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 02:59:46 2008''
+
 
 +
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Jul 28 13:45:05 2008''

Revision as of 10:45, 28 July 2008

Image:1nuj.png

Template:STRUCTURE 1nuj

THE LEADZYME STRUCTURE BOUND TO MG(H20)6(II) AT 1.8 A RESOLUTION

Template:ABSTRACT PUBMED 12911297

About this Structure

Full crystallographic information is available from OCA.

Reference

Crystal structure of the leadzyme at 1.8 A resolution: metal ion binding and the implications for catalytic mechanism and allo site ion regulation., Wedekind JE, McKay DB, Biochemistry. 2003 Aug 19;42(32):9554-63. PMID:12911297

Page seeded by OCA on Mon Jul 28 13:45:05 2008

Proteopedia Page Contributors and Editors (what is this?)

OCA

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