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.


1b4u

From Proteopedia

(Difference between revisions)
Jump to: navigation, search
Line 1: Line 1:
-
[[Image:1b4u.gif|left|200px]]
+
{{Seed}}
 +
[[Image:1b4u.png|left|200px]]
<!--
<!--
Line 9: Line 10:
{{STRUCTURE_1b4u| PDB=1b4u | SCENE= }}
{{STRUCTURE_1b4u| PDB=1b4u | SCENE= }}
-
'''PROTOCATECHUATE 4,5-DIOXYGENASE (LIGAB) IN COMPLEX WITH PROTOCATECHUATE (PCA)'''
+
===PROTOCATECHUATE 4,5-DIOXYGENASE (LIGAB) IN COMPLEX WITH PROTOCATECHUATE (PCA)===
-
==Overview==
+
<!--
-
BACKGROUND: Sphingomonas paucimobilis SYK-6 utilizes an extradiol-type catecholic dioxygenase, the LigAB enzyme (a protocatechuate 4,5-dioxygenase), to oxidize protocatechuate (or 3,4-dihydroxybenzoic acid, PCA). The enzyme belongs to the family of class III extradiol-type catecholic dioxygenases catalyzing the ring-opening reaction of protocatechuate and related compounds. The primary structure of LigAB suggests that the enzyme has no evolutionary relationship with the family of class II extradiol-type catecholic dioxygenases. Both the class II and class III enzymes utilize a non-heme ferrous center for adding dioxygen to the substrate. By elucidating the structure of LigAB, we aimed to provide a structural basis for discussing the function of class III enzymes. RESULTS: The crystal structure of substrate-free LigAB was solved at 2.2 A resolution. The molecule is an alpha2beta2 tetramer. The active site contains a non-heme iron coordinated by His12, His61, Glu242, and a water molecule located in a deep cleft of the beta subunit, which is covered by the alpha subunit. Because of the apparent oxidation of the Fe ion into the nonphysiological Fe(III) state, we could also solve the structure of LigAB complexed with a substrate, PCA. The iron coordination sphere in this complex is a distorted tetragonal bipyramid with one ligand missing, which is presumed to be the O2-binding site. CONCLUSIONS: The structure of LigAB is completely different from those of the class II extradiol-type dioxygenases exemplified by the BphC enzyme, a 2,3-dihydroxybiphenyl 1,2-dioxygenase from a Pseudomonas species. Thus, as already implicated by the primary structures, no evolutionary relationship exists between the class II and III enzymes. However, the two classes of enzymes share many geometrical characteristics with respect to the nature of the iron coordination sphere and the position of a putative catalytic base, strongly suggesting a common catalytic mechanism.
+
The line below this paragraph, {{ABSTRACT_PUBMED_10467151}}, adds the Publication Abstract to the page
 +
(as it appears on PubMed at http://www.pubmed.gov), where 10467151 is the PubMed ID number.
 +
-->
 +
{{ABSTRACT_PUBMED_10467151}}
==About this Structure==
==About this Structure==
Line 29: Line 33:
[[Category: Non-heme iron protein]]
[[Category: Non-heme iron protein]]
[[Category: Protocatechuate]]
[[Category: Protocatechuate]]
-
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 11:04:24 2008''
+
 
 +
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Jun 30 18:15:51 2008''

Revision as of 15:15, 30 June 2008

Image:1b4u.png

Template:STRUCTURE 1b4u

PROTOCATECHUATE 4,5-DIOXYGENASE (LIGAB) IN COMPLEX WITH PROTOCATECHUATE (PCA)

Template:ABSTRACT PUBMED 10467151

About this Structure

1B4U is a Protein complex structure of sequences from Sphingomonas paucimobilis. Full crystallographic information is available from OCA.

Reference

Crystal structure of an aromatic ring opening dioxygenase LigAB, a protocatechuate 4,5-dioxygenase, under aerobic conditions., Sugimoto K, Senda T, Aoshima H, Masai E, Fukuda M, Mitsui Y, Structure. 1999 Aug 15;7(8):953-65. PMID:10467151

Page seeded by OCA on Mon Jun 30 18:15:51 2008

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/1b4u"
Personal tools