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.


1qsb

From Proteopedia

(Difference between revisions)
Jump to: navigation, search
Line 1: Line 1:
-
[[Image:1qsb.gif|left|200px]]
+
{{Seed}}
 +
[[Image:1qsb.png|left|200px]]
<!--
<!--
Line 9: Line 10:
{{STRUCTURE_1qsb| PDB=1qsb | SCENE= }}
{{STRUCTURE_1qsb| PDB=1qsb | SCENE= }}
-
'''THE INTRODUCTION OF STRAIN AND ITS EFFECTS ON THE STRUCTURE AND STABILITY OF T4 LYSOZYME'''
+
===THE INTRODUCTION OF STRAIN AND ITS EFFECTS ON THE STRUCTURE AND STABILITY OF T4 LYSOZYME===
-
==Overview==
+
<!--
-
In order to try to better understand the role played by strain in the structure and stability of a protein a series of "small-to-large" mutations was made within the core of T4 lysozyme. Three different alanine residues, one involved in backbone contacts, one in side-chain contacts, and the third adjacent to a small cavity, were each replaced with subsets of the larger residues, Val, Leu, Ile, Met, Phe and Trp. As expected, the protein is progressively destabilized as the size of the introduced side-chain becomes larger. There does, however, seem to be a limit to the destabilization, suggesting that a protein of a given size may be capable of maintaining only a certain amount of strain. The changes in stability vary greatly from site to site. Substitution of larger residues for both Ala42 and Ala98 substantially destabilize the protein, even though the primary contacts in one case are predominantly with side-chain atoms and in the other with backbone. The results suggest that it is neither practical nor meaningful to try to separate the effects of introduced strain on side-chains from the effects on the backbone. Substitutions at Ala129 are much less destabilizing than at sites 42 or 98. This is most easily understood in terms of the pre-existing cavity, which provides partial space to accommodate the introduced side-chains. Crystal structures were obtained for a number of the mutants. These show that the changes in structure to accommodate the introduced side-chains usually consist of essentially rigid-body displacements of groups of linked atoms, achieved through relatively small changes in torsion angles. On rare occasions, a side-chain close to the site of substitution may change to a different rotamer. When such rotomer changes occur, they permit the structure to dissipate strain by a response that is plastic rather than elastic. In one case, a surface loop moves 1.2 A, not in direct response to a mutation, but in an interaction mediated via an intermolecular contact. It illustrates how the structure of a protein can be modified by crystal contacts.
+
The line below this paragraph, {{ABSTRACT_PUBMED_10623513}}, adds the Publication Abstract to the page
 +
(as it appears on PubMed at http://www.pubmed.gov), where 10623513 is the PubMed ID number.
 +
-->
 +
{{ABSTRACT_PUBMED_10623513}}
==About this Structure==
==About this Structure==
Line 31: Line 35:
[[Category: Strain]]
[[Category: Strain]]
[[Category: T4 lysozyme]]
[[Category: T4 lysozyme]]
-
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 06:38:52 2008''
+
 
 +
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Jul 27 16:59:11 2008''

Revision as of 13:59, 27 July 2008

Image:1qsb.png

Template:STRUCTURE 1qsb

THE INTRODUCTION OF STRAIN AND ITS EFFECTS ON THE STRUCTURE AND STABILITY OF T4 LYSOZYME

Template:ABSTRACT PUBMED 10623513

About this Structure

1QSB is a Single protein structure of sequence from Enterobacteria phage t4. Full crystallographic information is available from OCA.

Reference

The introduction of strain and its effects on the structure and stability of T4 lysozyme., Liu R, Baase WA, Matthews BW, J Mol Biol. 2000 Jan 7;295(1):127-45. PMID:10623513

Page seeded by OCA on Sun Jul 27 16:59:11 2008

Proteopedia Page Contributors and Editors (what is this?)

OCA

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