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Occurrence of bifurcated three‐center hydrogen bonds in protpins
Author(s) -
Preißner Robert,
Egner Ursula,
Saenger Wolfram
Publication year - 1991
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(91)81032-4
Subject(s) - hydrogen bond , crystallography , chemistry , center (category theory) , crystal structure , helix (gastropod) , stereochemistry , molecule , organic chemistry , biology , ecology , snail
Analysis of 13 high‐resolution protein X‐ray crystal structures shows that 1204 (24%) of all the 4974 hydrogen bonds are of the bifurcated three‐center type with the donor X‐H opposing two acceptors A1, A2. They occur systematically in α‐helices where 90% of the hydrogen bonds are of this type; the major component is (n+4)N‐H…O=C(n) as expected for a 3.6 13 α‐helix, and the minor component is (n+4)N‐H…O=C(n+1), as observed in 3 10 helices; distortions at the C‐temini of α‐helices are stabilized by three‐center bonds, In β‐sheets 40% of the hydrogen bonds are three‐centered. The frequent occurrence of three‐center hydrogen bonds suggests that they should not be neglected in protein structural studies.