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.


2af4

From Proteopedia

(Difference between revisions)
Jump to: navigation, search
Line 1: Line 1:
-
[[Image:2af4.gif|left|200px]]
+
{{Seed}}
 +
[[Image:2af4.png|left|200px]]
<!--
<!--
Line 9: Line 10:
{{STRUCTURE_2af4| PDB=2af4 | SCENE= }}
{{STRUCTURE_2af4| PDB=2af4 | SCENE= }}
-
'''Phosphotransacetylase from Methanosarcina thermophila co-crystallized with coenzyme A'''
+
===Phosphotransacetylase from Methanosarcina thermophila co-crystallized with coenzyme A===
-
==Overview==
+
<!--
-
Phosphotransacetylase (EC 2.3.1.8) catalyzes reversible transfer of the acetyl group from acetyl phosphate to coenzyme A (CoA), forming acetyl-CoA and inorganic phosphate. Two crystal structures of phosphotransacetylase from the methanogenic archaeon Methanosarcina thermophila in complex with the substrate CoA revealed one CoA (CoA1) bound in the proposed active site cleft and an additional CoA (CoA2) bound at the periphery of the cleft. The results of isothermal titration calorimetry experiments are described, and they support the hypothesis that there are distinct high-affinity (equilibrium dissociation constant [KD], 20 microM) and low-affinity (KD, 2 mM) CoA binding sites. The crystal structures indicated that binding of CoA1 is mediated by a series of hydrogen bonds and extensive van der Waals interactions with the enzyme and that there are fewer of these interactions between CoA2 and the enzyme. Different conformations of the protein observed in the crystal structures suggest that domain movements which alter the geometry of the active site cleft may contribute to catalysis. Kinetic and calorimetric analyses of site-specific replacement variants indicated that there are catalytic roles for Ser309 and Arg310, which are proximal to the reactive sulfhydryl of CoA1. The reaction is hypothesized to proceed through base-catalyzed abstraction of the thiol proton of CoA by the adjacent and invariant residue Asp316, followed by nucleophilic attack of the thiolate anion of CoA on the carbonyl carbon of acetyl phosphate. We propose that Arg310 binds acetyl phosphate and orients it for optimal nucleophilic attack. The hypothesized mechanism proceeds through a negatively charged transition state stabilized by hydrogen bond donation from Ser309.
+
The line below this paragraph, {{ABSTRACT_PUBMED_16428418}}, adds the Publication Abstract to the page
 +
(as it appears on PubMed at http://www.pubmed.gov), where 16428418 is the PubMed ID number.
 +
-->
 +
{{ABSTRACT_PUBMED_16428418}}
==About this Structure==
==About this Structure==
Line 20: Line 24:
==Reference==
==Reference==
Structural and functional studies suggest a catalytic mechanism for the phosphotransacetylase from Methanosarcina thermophila., Lawrence SH, Luther KB, Schindelin H, Ferry JG, J Bacteriol. 2006 Feb;188(3):1143-54. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/16428418 16428418]
Structural and functional studies suggest a catalytic mechanism for the phosphotransacetylase from Methanosarcina thermophila., Lawrence SH, Luther KB, Schindelin H, Ferry JG, J Bacteriol. 2006 Feb;188(3):1143-54. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/16428418 16428418]
 +
 +
Crystal structure of phosphotransacetylase from the methanogenic archaeon Methanosarcina thermophila., Iyer PP, Lawrence SH, Luther KB, Rajashankar KR, Yennawar HP, Ferry JG, Schindelin H, Structure. 2004 Apr;12(4):559-67. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/15062079 15062079]
[[Category: Methanosarcina thermophila]]
[[Category: Methanosarcina thermophila]]
[[Category: Phosphate acetyltransferase]]
[[Category: Phosphate acetyltransferase]]
Line 30: Line 36:
[[Category: Pta dimer with one coa ligand bound per monomer]]
[[Category: Pta dimer with one coa ligand bound per monomer]]
[[Category: Transferase]]
[[Category: Transferase]]
-
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 18:58:17 2008''
+
 
 +
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Jul 27 23:00:16 2008''

Revision as of 20:00, 27 July 2008

Image:2af4.png

Template:STRUCTURE 2af4

Phosphotransacetylase from Methanosarcina thermophila co-crystallized with coenzyme A

Template:ABSTRACT PUBMED 16428418

About this Structure

2AF4 is a Single protein structure of sequence from Methanosarcina thermophila. Full crystallographic information is available from OCA.

Reference

Structural and functional studies suggest a catalytic mechanism for the phosphotransacetylase from Methanosarcina thermophila., Lawrence SH, Luther KB, Schindelin H, Ferry JG, J Bacteriol. 2006 Feb;188(3):1143-54. PMID:16428418

Crystal structure of phosphotransacetylase from the methanogenic archaeon Methanosarcina thermophila., Iyer PP, Lawrence SH, Luther KB, Rajashankar KR, Yennawar HP, Ferry JG, Schindelin H, Structure. 2004 Apr;12(4):559-67. PMID:15062079

Page seeded by OCA on Sun Jul 27 23:00:16 2008

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/2af4"
Personal tools