Open AccessThe alpha aneurism: a structural motif revealed in an insertion mutant of staphylococcal nuclease.
Author(s) -
Lisa J. Keefe,
John Sondek,
David Shortle,
Eaton E. Lattman
Publication year - 1993
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.90.8.3275
Subject(s) - mutant , nuclease , chemistry , mutant protein , protein structure , threading (protein sequence) , crystallography , biochemistry , dna , gene
The x-ray crystal structure of a mutant of staphylococcal nuclease that contains a single glycine residue inserted in the C-terminal alpha-helix has been solved to 1.67 A resolution and refined to a crystallographic R value of 0.170. This inserted glycine residue is accommodated in the alpha-helix by formation of a previously uncharacterized bulge, which we term the alpha aneurism. A conformational search of known protein structures has identified the alpha aneurism in a number of protein families, including the histocompatibility antigens and hemoglobins.