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Geometry of guanidinium groups in arginines
Author(s) -
Malinska Maura,
Dauter Miroslawa,
Dauter Zbigniew
Publication year - 2016
Publication title -
protein science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.353
H-Index - 175
eISSN - 1469-896X
pISSN - 0961-8368
DOI - 10.1002/pro.2970
Subject(s) - guanidinium chloride , computational biology , chemistry , stereochemistry , biology , crystallography , evolutionary biology , biochemistry , enzyme
The restraints in common usage today have been obtained based on small molecule X‐ray crystal structures available 25 years ago and recent reports have shown that the values of bond lengths and valence angles can be, in fact, significantly different from those stored in libraries, for example for the peptide bond or the histidine ring geometry. We showed that almost 50% of outliers found in protein validation reports released in the Protein Data Bank on 23 March 2016 come from geometry of guanidine groups in arginines. Therefore, structures of small molecules and atomic resolution protein crystal structures have been used to derive new target values for the geometry of this group. The most significant difference was found for NE‐CZ‐NH1 and NE‐CZ‐NH2 angles, showing that the guanidinium group is not symmetric. The NE‐CZ‐NH1 angle is larger, 121.5(10)˚, than NE‐CZ‐NH2, 119.2(10)˚, due to the repulsive interaction between NH1 and CD1 atom.