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Crystal structure of a 1.6‐hexanediol bound tetrameric form of Escherichia coli Lac‐repressor refined to 2.1 Å resolution
Author(s) -
Stenberg Kaj A. E.,
Vihinen Mauno
Publication year - 2008
Publication title -
proteins: structure, function, and bioinformatics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.699
H-Index - 191
eISSN - 1097-0134
pISSN - 0887-3585
DOI - 10.1002/prot.22284
Subject(s) - tetramer , lac repressor , escherichia coli , repressor , chemistry , context (archaeology) , resolution (logic) , function (biology) , crystallography , monomer , stereochemistry , lac operon , biochemistry , biology , genetics , gene , paleontology , organic chemistry , artificial intelligence , computer science , transcription factor , enzyme , polymer
We report the structure of a novel tetrameric form of the lactose repressor (LacI) protein from Escherichia coli refined to 2.1 Å resolution. The tetramer is bound to 1.6‐hexanediol present in the crystallization solution and the final R free for the structure is 0.201. The structure confirms previously reported structures on the monomer level. However, the tetramer is much more densely packed. This adds a new level of complexity to the interpretation of mutational effects and challenges details in the current model for LacI function. Several amino acids, previously associated with changes in function but unexplained at the structural level, appear in a new structural context in this tetramer which provides new implications for their function. Proteins 2009. © 2008 Wiley‐Liss, Inc.