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X-ray crystal structure of MENT: evidence for functional loop-sheet polymers in chromatin condensation.

Authors :
McGowan S
Buckle AM
Irving JA
Ong PC
Bashtannyk-Puhalovich TA
Kan WT
Henderson KN
Bulynko YA
Popova EY
Smith AI
Bottomley SP
Rossjohn J
Grigoryev SA
Pike RN
Whisstock JC
Source :
The EMBO journal [EMBO J] 2006 Jul 12; Vol. 25 (13), pp. 3144-55. Date of Electronic Publication: 2006 Jun 29.
Publication Year :
2006

Abstract

Most serpins are associated with protease inhibition, and their ability to form loop-sheet polymers is linked to conformational disease and the human serpinopathies. Here we describe the structural and functional dissection of how a unique serpin, the non-histone architectural protein, MENT (Myeloid and Erythroid Nuclear Termination stage-specific protein), participates in DNA and chromatin condensation. Our data suggest that MENT contains at least two distinct DNA-binding sites, consistent with its simultaneous binding to the two closely juxtaposed linker DNA segments on a nucleosome. Remarkably, our studies suggest that the reactive centre loop, a region of the MENT molecule essential for chromatin bridging in vivo and in vitro, is able to mediate formation of a loop-sheet oligomer. These data provide mechanistic insight into chromatin compaction by a non-histone architectural protein and suggest how the structural plasticity of serpins has adapted to mediate physiological, rather than pathogenic, loop-sheet linkages.

Details

Language :
English
ISSN :
0261-4189
Volume :
25
Issue :
13
Database :
MEDLINE
Journal :
The EMBO journal
Publication Type :
Academic Journal
Accession number :
16810322
Full Text :
https://doi.org/10.1038/sj.emboj.7601201