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.


1q0c

From Proteopedia

(Difference between revisions)
Jump to: navigation, search
Line 1: Line 1:
-
[[Image:1q0c.jpg|left|200px]]
+
{{Seed}}
 +
[[Image:1q0c.png|left|200px]]
<!--
<!--
Line 9: Line 10:
{{STRUCTURE_1q0c| PDB=1q0c | SCENE= }}
{{STRUCTURE_1q0c| PDB=1q0c | SCENE= }}
-
'''Anerobic Substrate Complex of Homoprotocatechuate 2,3-Dioxygenase from Brevibacterium fuscum. (Complex with 3,4-Dihydroxyphenylacetate)'''
+
===Anerobic Substrate Complex of Homoprotocatechuate 2,3-Dioxygenase from Brevibacterium fuscum. (Complex with 3,4-Dihydroxyphenylacetate)===
-
==Overview==
+
<!--
-
The X-ray crystal structures of homoprotocatechuate 2,3-dioxygenases isolated from Arthrobacter globiformis and Brevibacterium fuscum have been determined to high resolution. These enzymes exhibit 83% sequence identity, yet their activities depend on different transition metals, Mn2+ and Fe2+, respectively. The structures allow the origins of metal ion selectivity and aspects of the molecular mechanism to be examined in detail. The homotetrameric enzymes belong to the type I family of extradiol dioxygenases (vicinal oxygen chelate superfamily); each monomer has four betaalphabetabetabeta modules forming two structurally homologous N-terminal and C-terminal barrel-shaped domains. The active-site metal is located in the C-terminal barrel and is ligated by two equatorial ligands, H214NE1 and E267OE1; one axial ligand, H155NE1; and two to three water molecules. The first and second coordination spheres of these enzymes are virtually identical (root mean square difference over all atoms, 0.19 A), suggesting that the metal selectivity must be due to changes at a significant distance from the metal and/or changes that occur during folding. The substrate (2,3-dihydroxyphenylacetate [HPCA]) chelates the metal asymmetrically at sites trans to the two imidazole ligands and interacts with a unique, mobile C-terminal loop. The loop closes over the bound substrate, presumably to seal the active site as the oxygen activation process commences. An "open" coordination site trans to E267 is the likely binding site for O2. The geometry of the enzyme-substrate complexes suggests that if a transiently formed metal-superoxide complex attacks the substrate without dissociation from the metal, it must do so at the C-3 position. Second-sphere active-site residues that are positioned to interact with the HPCA and/or bound O2 during catalysis are identified and discussed in the context of current mechanistic hypotheses.
+
The line below this paragraph, {{ABSTRACT_PUBMED_15028678}}, adds the Publication Abstract to the page
 +
(as it appears on PubMed at http://www.pubmed.gov), where 15028678 is the PubMed ID number.
 +
-->
 +
{{ABSTRACT_PUBMED_15028678}}
==About this Structure==
==About this Structure==
Line 30: Line 34:
[[Category: Extradiol dioxygenase]]
[[Category: Extradiol dioxygenase]]
[[Category: Substrate complex]]
[[Category: Substrate complex]]
-
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 05:42:41 2008''
+
 
 +
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Tue Jul 29 04:20:42 2008''

Revision as of 01:20, 29 July 2008

Image:1q0c.png

Template:STRUCTURE 1q0c

Anerobic Substrate Complex of Homoprotocatechuate 2,3-Dioxygenase from Brevibacterium fuscum. (Complex with 3,4-Dihydroxyphenylacetate)

Template:ABSTRACT PUBMED 15028678

About this Structure

1Q0C is a Single protein structure of sequence from Brevibacterium fuscum. Full crystallographic information is available from OCA.

Reference

Crystallographic comparison of manganese- and iron-dependent homoprotocatechuate 2,3-dioxygenases., Vetting MW, Wackett LP, Que L Jr, Lipscomb JD, Ohlendorf DH, J Bacteriol. 2004 Apr;186(7):1945-58. PMID:15028678

Page seeded by OCA on Tue Jul 29 04:20:42 2008

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/1q0c"
Personal tools