Interaction of chromatin with a histone H1 containing swapped N- and C-terminal domains |
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| Authors: | Jordana?B Hutchinson Manjinder?S Cheema Jason Wang Krystal Missiaen Ron Finn Rodrigo Gonzalez Romero John?P H Th’ng Michael Hendzel Juan Ausió |
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| Institution: | *Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada V8W 3P6;†Department of Oncology, Faculty of Dentistry and Medicine, University of Alberta, Edmonton, Alberta, Canada T6G 1Z2;‡Northern Ontario School of Medicine, 955 Oliver Road, Thunder Bay, Ontario, Canada P7B 5E1 |
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| Abstract: | Although the details of the structural involvement of histone H1 in the organization of the nucleosome are quite well understood, the sequential events involved in the recognition of its binding site are not as well known. We have used a recombinant human histone H1 (H1.1) in which the N- and C-terminal domains (NTD/CTD) have been swapped and we have reconstituted it on to a 208-bp nucleosome. We have shown that the swapped version of the protein is still able to bind to nucleosomes through its structurally folded wing helix domain (WHD); however, analytical ultracentrifuge analysis demonstrates its ability to properly fold the chromatin fibre is impaired. Furthermore, FRAP analysis shows that the highly dynamic binding association of histone H1 with the chromatin fibre is altered, with a severely decreased half time of residence. All of this suggests that proper binding of histone H1 to chromatin is determined by the simultaneous and synergistic binding of its WHD–CTD to the nucleosome. |
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| Keywords: | analytical ultracentrifuge chromatin circular dichroism FRAP histones |
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