PDBsum entry 1e6h

Sh3-domain

PDB id: 1e6h

Contents

Protein chain

61 a.a. *

Waters ×65

* Residue conservation analysis

PDB id:

1e6h

Name:

Sh3-domain

Title:

A-spectrin sh3 domain a11v, m25i, v44i, v58l mutants

Structure:

Spectrin alpha chain. Chain: a. Fragment: sh3-domain residues 964-1025. Engineered: yes. Mutation: yes

Source:

Gallus gallus. Chicken. Organism_taxid: 9031. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.

Resolution:

2.01Å R-factor: 0.257 R-free: 0.276

Authors:

M.C.Vega,L.Serrano

Key ref:

S.Ventura et al. (2002). Conformational strain in the hydrophobic core and its implications for protein folding and design. Nat Struct Biol, 9, 485-493. PubMed id: 12006985 DOI: 10.1038/nsb799

Date:

17-Aug-00 Release date: 23-May-02

Protein chain

P07751  (SPTN1_CHICK) -  Spectrin alpha chain, non-erythrocytic 1 from Gallus gallus

Seq: 2477 a.a.

Struc: 61 a.a.*

* PDB and UniProt seqs differ at 4 residue positions (black crosses)

DOI no: 10.1038/nsb799

Nat Struct Biol 9:485-493 (2002)

PubMed id: 12006985

Conformational strain in the hydrophobic core and its implications for protein folding and design.

S.Ventura, M.C.Vega, E.Lacroix, I.Angrand, L.Spagnolo, L.Serrano.

ABSTRACT

We have designed de novo 13 divergent spectrin SH3 core sequences to determine their folding properties. Kinetic analysis of the variants with stability similar to that of the wild type protein shows accelerated unfolding and refolding rates compatible with a preferential stabilization of the transition state. This is most likely caused by conformational strain in the native state, as deletion of a methyl group (Ile-->Val) leads to deceleration in unfolding and increased stability (up to 2 kcal x mol(-1)). Several of these Ile-->Val mutants have negative phi(-U) values, indicating that some noncanonical phi(-U) values might result from conformational strain. Thus, producing a stable protein does not necessarily mean that the design process has been entirely successful. Strained interactions could have been introduced, and a reduction in the buried volume could result in a large increase in stability and a reduction in unfolding rates.

Selected figure(s)

Figure 4.
Figure 4. Folding and unfolding kinetic curves of the WT, spectrin SH3 and core mutants.

Figure 5.
Figure 5. Stereo view of the omit map of the core residues. a, Best4; b, C8A; and c, C8A-I25V mutants contoured at 1 level. The orientation of the hydrophobic core is identical to those in Fig. 6.

The above figures are reprinted by permission from Macmillan Publishers Ltd: Nat Struct Biol (2002, 9, 485-493) copyright 2002.

Figures were selected by an automated process.