Plasticity within the obligatory folding nucleus of an immunoglobulin-like domain

JOURNAL OF MOLECULAR BIOLOGY

卷:375

Article

Lappalainen, Ilkka¹  Hurley, Michael G.¹  Clarke, Jane¹ 

[1] Univ Cambridge, Dept Chem, MRC Ctr Prot Engn, Cambridge CB2 1EW, England

关键词: folding nucleus;    protein folding;    phi-value analysis;    Ig domain;   

DOI  :  10.1016/j.jmb.2007.09.088

来源: Elsevier

【 摘 要 】

A number of beta-sandwich immunoglobulin-like domains have been shown to fold using a set of structurally equivalent residues that form a folding nucleus deep within the core of the protein. Formation of this nucleus is sufficient to establish the complex Greek key topology of the native state. These nucleating residues are highly conserved within the immunoglobulin superfamily, but are less well conserved in the fibronectin type III (fnIII) superfamily, where the requirement is simply to have four interacting hydrophobic residues. However, there are rare examples where this nucleation pattern is absent. In this study, we have investigated the folding of a novel member of the fnIII superfamily whose nucleus appears to lack one of the four buried hydrophobic residues. We show that the folding mechanism is unaltered, but the folding nucleus has moved within the hydrophobic core. (C) 2007 Elsevier Ltd. All rights reserved.

【 授权许可】

Free