2qbu

From Proteopedia

(Difference between revisions)
Jump to: navigation, search
(New page: 200px <!-- The line below this paragraph, containing "STRUCTURE_2qbu", creates the "Structure Box" on the page. You may change the PDB parameter (which sets the PD...)
Line 1: Line 1:
-
[[Image:2qbu.jpg|left|200px]]
+
{{Seed}}
 +
[[Image:2qbu.png|left|200px]]
<!--
<!--
Line 9: Line 10:
{{STRUCTURE_2qbu| PDB=2qbu | SCENE= }}
{{STRUCTURE_2qbu| PDB=2qbu | SCENE= }}
-
'''Crystal structure of Methanothermobacter thermautotrophicus CbiL'''
+
===Crystal structure of Methanothermobacter thermautotrophicus CbiL===
-
==Overview==
+
<!--
-
Ring contraction during cobalamin (vitamin B12) biosynthesis requires a seemingly futile methylation of the C20 position of the tetrapyrrole framework. Along the anaerobic route, this reaction is catalyzed by CbiL, which transfers a methyl group from S-adenosyl-L-methionine to cobalt factor II to generate cobalt factor III. CbiL belongs to the class III methyltransferases and displays similarity to other cobalamin biosynthetic methyltransferases that are responsible for the regiospecific methylation of a number of positions on the tetrapyrrole molecular canvas. In an attempt to understand how CbiL selectively methylates the C20 position, a detailed structure function analysis of the enzyme has been undertaken. In this paper, we demonstrate that the enzyme methylates the C20 position, that its preferred substrate is cobalt factor II, and that the metal ion does not undergo any oxidation change during the course of the reaction. The enzyme was crystallized, and its structure was determined by x-ray crystallography, revealing that the 26-kDa protein has a similar overall topology to other class III enzymes. This helped in the identification of some key amino acid residues (Asp(104), Lys(176), and Tyr(220)). Analysis of mutant variants of these groups has allowed us to suggest potential roles that these side chains may play in substrate binding and catalysis. EPR analysis of binary and ternary complexes indicate that the protein donates a fifth ligand to the cobalt ion via a gated mechanism to prevent transfer of the methyl group to water. The chemical logic underpinning the methylation is discussed.
+
The line below this paragraph, {{ABSTRACT_PUBMED_17567575}}, adds the Publication Abstract to the page
 +
(as it appears on PubMed at http://www.pubmed.gov), where 17567575 is the PubMed ID number.
 +
-->
 +
{{ABSTRACT_PUBMED_17567575}}
==About this Structure==
==About this Structure==
Line 26: Line 30:
[[Category: Warren, M J.]]
[[Category: Warren, M J.]]
[[Category: Methyltransferase]]
[[Category: Methyltransferase]]
-
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Wed Apr 16 23:05:02 2008''
+
 
 +
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Jul 27 13:23:08 2008''

Revision as of 10:23, 27 July 2008

Image:2qbu.png

Template:STRUCTURE 2qbu

Crystal structure of Methanothermobacter thermautotrophicus CbiL

Template:ABSTRACT PUBMED 17567575

About this Structure

2QBU is a Single protein structure of sequence from Methanothermobacter thermautotrophicus. Full crystallographic information is available from OCA.

Reference

Elucidation of substrate specificity in the cobalamin (vitamin B12) biosynthetic methyltransferases. Structure and function of the C20 methyltransferase (CbiL) from Methanothermobacter thermautotrophicus., Frank S, Deery E, Brindley AA, Leech HK, Lawrence A, Heathcote P, Schubert HL, Brocklehurst K, Rigby SE, Warren MJ, Pickersgill RW, J Biol Chem. 2007 Aug 17;282(33):23957-69. Epub 2007 Jun 13. PMID:17567575

Page seeded by OCA on Sun Jul 27 13:23:08 2008

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/2qbu"
Personal tools