International
Tables for Crystallography Volume F Crystallography of biological macromolecules Edited by M. G. Rossmann and E. Arnold © International Union of Crystallography 2006 |
International Tables for Crystallography (2006). Vol. F. ch. 22.2, pp. 548-549
Section 22.2.5.3.2. β-sheets
aSchool of Biological Sciences, University of Auckland, Private Bag 92-109, Auckland, New Zealand |
β-sheets consist of short strands of polypeptide (typically 5–7 residues) running parallel or antiparallel and cross-linked by N—H···O=C hydrogen bonds. Although the (φ, ψ) angles of residues within β-sheets can be quite variable, the hydrogen-bonding patterns within these segments tend to be quite regular, as in the original Pauling models (Pauling & Corey, 1951). Occasional β-bulges in the middle of β-strands can interrupt the hydrogen-bonding pattern (Richardson et al., 1978), but otherwise disruptions occur only at the ends of strands. The hydrogen bonds in β-sheets appear to be slightly shorter than those in helices, by ∼0.1 Å, and also more linear (N—H···O ∼ 160°, compared with ∼157° in helices) (Baker & Hubbard, 1984). There also appears to be no difference between parallel and antiparallel β-sheets in the hydrogen-bond lengths and angles.
References
Baker, E. N. & Hubbard, R. E. (1984). Hydrogen bonding in globular proteins. Prog. Biophys. Mol. Biol. 44, 97–179.Google ScholarPauling, L. & Corey, R. B. (1951). Configurations of polypeptide chains with favoured orientations around single bonds: two new pleated sheets. Proc. Natl Acad. Sci. USA, 37, 729–740.Google Scholar
Richardson, J. S., Getzoff, E. D. & Richardson, D. C. (1978). The β-bulge: a common small unit of nonrepetitive protein structure. Proc. Natl Acad. Sci. USA, 75, 2574–2578.Google Scholar