ISSN:
0887-3585
Keywords:
calcium binding
;
crystal structure
;
protein stability
;
site-directed mutagenesis
;
subtilisin
;
X-ray crystallography
;
Chemistry
;
Biochemistry and Biotechnology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Medicine
Notes:
A version of subtilisin BPN′ lacking the high affinity calcium site (site A) has been produced through genetic engineering methods, and its crystal structure refined at 1.8 Å resolution. This protein and the corresponding version containing the calcium A site are describedand compared. The deletion of residues 75-83 was made in the context of four site-specific replacements previously shown to stabilize subtilisin. The helix that in wild type is interrupted by the calcium binding loop, is continuous in the deletion mutant, with normal geometry. A few residues adjacent to the loop, principally those that were involved in calcium coordination, are repositioned and/or destabilized by the deletion. Because refolding is greatly facilitated by the absence of the Caloop, this proteinoffers a new vehicle for analysis and dissection of the folding reaction. This is among the largest internal changes to a protein to be described at atomic resolution. © Wiley-Liss, Inc.
Additional Material:
8 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/prot.340160207
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