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.


2vgw

From Proteopedia

(Difference between revisions)
Jump to: navigation, search
Line 1: Line 1:
-
[[Image:2vgw.jpg|left|200px]]
+
{{Seed}}
 +
[[Image:2vgw.png|left|200px]]
<!--
<!--
Line 9: Line 10:
{{STRUCTURE_2vgw| PDB=2vgw | SCENE= }}
{{STRUCTURE_2vgw| PDB=2vgw | SCENE= }}
-
'''CRYSTAL STRUCTURE OF E53QBSSHMT OBTAINED IN THE PRESENCE OF GLYCINE AND 5-FOMYL TETRAHYDROFOLATE'''
+
===CRYSTAL STRUCTURE OF E53QBSSHMT OBTAINED IN THE PRESENCE OF GLYCINE AND 5-FOMYL TETRAHYDROFOLATE===
-
==Overview==
+
<!--
-
Serine hydroxymethyltransferase (SHMT) belongs to the alpha-family of pyridoxal 5'-phosphate-dependent enzymes and catalyzes the reversible conversion of L-Ser and tetrahydrofolate to Gly and 5,10-methylene tetrahydrofolate. 5,10-Methylene tetrahydrofolate serves as a source of one-carbon fragment in many biological processes. SHMT also catalyzes the tetrahydrofolate-independent conversion of L-allo-Thr to Gly and acetaldehyde. The crystal structure of Bacillus stearothermophilus SHMT (bsSHMT) suggested that E53 interacts with the substrate, L-Ser and tetrahydrofolate. To elucidate the role of E53, it was mutated to Q and structural and biochemical studies were carried out with the mutant enzyme. The internal aldimine structure of E53QbsSHMT was similar to that of the wild-type enzyme, except for significant changes at Q53, Y60 and Y61. The carboxyl of Gly and side chain of L-Ser were in two conformations in the respective external aldimine structures. The mutant enzyme was completely inactive for tetrahydrofolate-dependent cleavage of L-Ser, whereas there was a 1.5-fold increase in the rate of tetrahydrofolate-independent reaction with L-allo-Thr. The results obtained from these studies suggest that E53 plays an essential role in tetrahydrofolate/5-formyl tetrahydrofolate binding and in the proper positioning of Cbeta of L-Ser for direct attack by N5 of tetrahydrofolate. Most interestingly, the structure of the complex obtained by cocrystallization of E53QbsSHMT with Gly and 5-formyl tetrahydrofolate revealed the gem-diamine form of pyridoxal 5'-phosphate bound to Gly and active site Lys. However, density for 5-formyl tetrahydrofolate was not observed. Gly carboxylate was in a single conformation, whereas pyridoxal 5'-phosphate had two distinct conformations. The differences between the structures of this complex and Gly external aldimine suggest that the changes induced by initial binding of 5-formyl tetrahydrofolate are retained even though 5-formyl tetrahydrofolate is absent in the final structure. Spectral studies carried out with this mutant enzyme also suggest that 5-formyl tetrahydrofolate binds to the E53QbsSHMT-Gly complex forming a quinonoid intermediate and falls off within 4 h of dialysis, leaving behind the mutant enzyme in the gem-diamine form. This is the first report to provide direct evidence for enzyme memory based on the crystal structure of enzyme complexes.
+
The line below this paragraph, {{ABSTRACT_PUBMED_17651438}}, adds the Publication Abstract to the page
 +
(as it appears on PubMed at http://www.pubmed.gov), where 17651438 is the PubMed ID number.
 +
-->
 +
{{ABSTRACT_PUBMED_17651438}}
==About this Structure==
==About this Structure==
Line 38: Line 42:
[[Category: Shmt]]
[[Category: Shmt]]
[[Category: Transferase]]
[[Category: Transferase]]
-
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun May 4 18:47:31 2008''
+
 
 +
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Jul 27 17:55:23 2008''

Revision as of 14:55, 27 July 2008

Image:2vgw.png

Template:STRUCTURE 2vgw

CRYSTAL STRUCTURE OF E53QBSSHMT OBTAINED IN THE PRESENCE OF GLYCINE AND 5-FOMYL TETRAHYDROFOLATE

Template:ABSTRACT PUBMED 17651438

About this Structure

2VGW is a Single protein structure of sequence from Geobacillus stearothermophilus. Full crystallographic information is available from OCA.

Reference

Structure determination and biochemical studies on Bacillus stearothermophilus E53Q serine hydroxymethyltransferase and its complexes provide insights on function and enzyme memory., Rajaram V, Bhavani BS, Kaul P, Prakash V, Appaji Rao N, Savithri HS, Murthy MR, FEBS J. 2007 Aug;274(16):4148-60. Epub 2007 Jul 25. PMID:17651438

Page seeded by OCA on Sun Jul 27 17:55:23 2008

Proteopedia Page Contributors and Editors (what is this?)

OCA

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