Side-chains configurations in coiled coils revealed by the 5.15-A meridional reflection on hard alpha-keratin X-ray diffraction patterns.
The origin of the 5.15-A meridional reflection on hard alpha-keratin X-ray diffraction patterns is discussed in terms of side-chains conformations. We show it to reveal specific configurations of the side chains which are common to all two-stranded alpha-helical coiled coils. Combining literature data on crystallised coiled coil pieces and molecular dynamics results with our X-ray diffraction pattern simulations, we propose rules for the attribution of chi1 torsion angles for coiled coils involved in fibres whose structure cannot be resolved at atomic resolution: in a (a b c d e f g) heptad repeat, a and d residues, respectively, adopt mean t and g+ configurations, whereas statistical rules are given for the other residues.
Busson
B
B
LURE, Bât 209-D, Université Paris-Sud, Orsay cedex, F-91898, France.
Briki
F
F
Doucet
J
J
D001426:Bacterial Proteins / Q000737:chemistry; D004268:DNA-Binding Proteins; D005656:Fungal Proteins / Q000737:chemistry; D007633:Keratins / Q000737:chemistry*; D008074:Lipoproteins / Q000737:chemistry; D011487:Protein Conformation; D011494:Protein Kinases / Q000737:chemistry; D017433:Protein Structure, Secondary; D029701:Saccharomyces cerevisiae Proteins; D014961:X-Ray Diffraction
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D008074:Lipoproteins; D029701:Saccharomyces cerevisiae Proteins; D007633:Keratins; D011494:Protein Kinases