Self-association of the globular domain of histone H5.
The capacity of the globular domain of the chicken erythrocyte linker histone H5 (GH5) to self-associate in solution has been demonstrated by chemical cross-linking with dimethyl 3,3'-dithiobis-(propionimidate) (DTBP), dithiobis(succinimidyl propionate) (DSP), and 3,3'-dithiobis(sulfosuccinimidyl propionate) (DTSSP). Several observations suggest that the GH5-GH5 interactions that mediate self-association are specific: (a) Incubation with each of the above reagents produces a discrete and characteristic pattern of cross-linked products; (b) GH1, the related peptide from chicken erythrocyte H1, is not cross-linked under the same conditions; (c) GH5 is not cross-linked with disuccinimidyl tartrate (DST), which has a shorter cross-linking span (6.4 A) than the other reagents (12 A); and (d) analysis of cross-linking as a function of peptide concentration provides an equilibrium constant for GH5 self-association of (4.8 +/- 1.3) x 10(3) M-1. The ability of GH5 to specifically self-associate is compatible with the proposal [Thoma, F., Koller, T., & Klug, A. (1979) J. Cell Biol. 83, 403-427] that linker histone globular domains occupy an axial position within the higher order chromatin fiber; the spatial juxtaposition of the GH5 domains at this location would be expected to promote their association and exert a stabilizing effect upon higher order chromatin structure.
Maman
J D
JD
Department of Biochemistry, Edinburgh University, United Kingdom.
Yager
T D
TD
Allan
J
J
D000818:Animals; D002645:Chickens / Q000097:blood; D002942:Circular Dichroism; D003432:Cross-Linking Reagents; D004912:Erythrocytes / Q000737:chemistry; D006657:Histones / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007096:Imidoesters; D046911:Macromolecular Substances; D008958:Models, Molecular; D009994:Osmolar Concentration; D017510:Protein Folding; D017433:Protein Structure, Secondary; D012965:Sodium Chloride / Q000494:pharmacology; D012996:Solutions; D013388:Succinimides; D014357:Trypsin / Q000494:pharmacology
D003432:Cross-Linking Reagents; D006657:Histones; D007096:Imidoesters; D046911:Macromolecular Substances; D012996:Solutions; D013388:Succinimides; D012965:Sodium Chloride; C007471:dimethyl dithiobispropionimidate; C035759:3,3'-dithiobis(sulfosuccinimidyl propionate); D014357:Trypsin; C011240:dithiobis(succinimidylpropionate)