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Title: Membrane association of active genes organizes the chloroplast nucleoid structure
DNA is organized into chromatin-like structures that support the maintenance and regulation of genomes. A unique and poorly understood form of DNA organization exists in chloroplasts, which are organelles of endosymbiotic origin responsible for photosynthesis. Chloroplast genomes, together with associated proteins, form membrane-less structures known as nucleoids. The internal arrangement of the nucleoid, molecular mechanisms of DNA organization, and connections between nucleoid structure and gene expression remain mostly unknown. We show thatArabidopsis thalianachloroplast nucleoids have a unique sequence-specific organization driven by DNA binding to the thylakoid membranes. DNA associated with the membranes has high protein occupancy, has reduced DNA accessibility, and is highly transcribed. In contrast, genes with low levels of transcription are further away from the membranes, have lower protein occupancy, and have higher DNA accessibility. Membrane association of active genes relies on the pattern of transcription and proper chloroplast development. We propose a speculative model that transcription organizes the chloroplast nucleoid into a transcriptionally active membrane-associated core and a less active periphery.  more » « less
Award ID(s):
1934703
PAR ID:
10531343
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ;
Publisher / Repository:
PNAS
Date Published:
Journal Name:
Proceedings of the National Academy of Sciences
Volume:
121
Issue:
28
ISSN:
0027-8424
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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