The alpha aneurism: a structural motif revealed in an insertion mutant of staphylococcal nuclease.
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.
Keefe
L J
LJ
Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205-2185.
Sondek
J
J
Shortle
D
D
Lattman
E E
EE
D000595:Amino Acid Sequence; D001120:Arginine; D002151:Calorimetry; D006860:Hydrogen Bonding; D008239:Lysine; D008836:Micrococcal Nuclease / Q000737:chemistry* / Q000235:genetics*; D008958:Models, Molecular; D016254:Mutagenesis, Insertional; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D014961:X-Ray Diffraction / Q000379:methods
D001120:Arginine; D008836:Micrococcal Nuclease; D008239:Lysine