Original scientific paper

Molecular structure of spinach chloroplast nucleoids

Hrvoje Fulgosi ; Ruđer Bošković Institute, Department of Molecular Genetics, Zagreb, Croatia
Nikola Ljubešić ; Ruđer Bošković Institute, Department of Molecular Genetics, Zagreb, Croatia

Abstract

The ultrastructure and molecular composition of spinach chloroplast nucleoids were studied. Isolated nucleoids retained their three-dimensionally folded structure observed in situ. Fluorescence microscopy and staining with DAP1 reaffirmed the mostly DNA-containing nature of these complexes. The presence of chloroplast DNA was confirmed by restriction fragment analysis. Electron microscopy revealed a highly condensed, chromatin-like, beaded substructure. Naked DNA supercoils or loops were not observed. Integral nucleoid proteins were isolated and analysed on SDS-polyacrylamide gels. A distinct pattern of the nucleoid proteins, covering the entire range of molecular masses from 5 kDa to >100 kDa revealed that the nucleoid fraction was highly depleted of major thylakoid and stromal constituents.

Keywords

spinach; chloroplast nucleoides; cpDNA; proteins; microscopy

Hrčak ID:

160581

URI

https://hrcak.srce.hr/160581

Publication date:

31.12.1999.

Article data in other languages: croatian

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