Premium
Origin of replication in chloroplast DNA of Euglena gracilis located close to the region of variable size
Author(s) -
Koller Barbara,
Delius Hajo
Publication year - 1982
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1002/j.1460-2075.1982.tb01283.x
Subject(s) - biology , euglena gracilis , restriction enzyme , bamhi , chloroplast dna , genetics , dna replication , dna , microbiology and biotechnology , chloroplast , gene
Chloroplast DNA (cpDNA), containing ˜10% replicative molecules, was isolated 2 h after onset of the dark period from cultures of Euglena gracilis strain Z. The DNA was digested with the restriction enzymes Pvu II, Sal I, Bam HI, or Eco RI. Fragments that contained intact replicative loops were measured to determine the position of replicated sequences in relation to the restriction enzyme sites. It was found that replication starts at a unique position near one of the palindromic sequences I 2 (Koller and Delius, 1982a) which is located upstream (with respect to the direction of rRNA transcription) of the AT‐rich region of variable size (Jenni et al., 1981; Schlunegger et al., in preparation). In the majority of cases DNA synthesis proceeds unidirectionally away from this region for ˜5000 nucleotides before it starts in the other direction (in the same sense as the rRNA transcription) through the Z‐region and the second palindromic sequence.