Structure and function of a chloroplast DNA replication origin of Chlamydomonas reinhardtii

Abstract

Chloroplast DNA replication in Chlamydomonas reinhardtii is initiated by the formation of a displacement loop (D-loop) at a specific site. One D-loop site with its flanking sequence was cloned in recombinant plasmids SC3-1 and R-13. The sequence of the chloroplast DNA insert in SC3-1, which includes the 0.42-kilobase (kb) D-loop region, as well as 0.2 kb to the 5' end and 0.43 kb to the 3' end of the D-loop region, was determined. The sequence is A+T-rich 6761The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement"in accordance with 18 U.S.C. §1734 solely to indicate this fact.

Localization of replication origins in pea chloroplast DNA.

“…1, its In summary, the positioning of the ori-specific sequences in ctDNA may have a general characteristic of proximity to the rRNA genes but a flexible positioning relative to them. Also, those reports (3,4,16,21) on the base composition of the chloroplast-specific ori regions have, in general, found them to be A+T rich, and our data from a higher plant are clearly in agreement with this property. It will be highly interesting to determine and explore the precise base sequences of the two pea ctDNA D-loop regions mapped here and then to compare the various properties of a higher plant ctDNA replicative region with the properties of its counterpart in the algal replicative region.…”

“…Waddell et al (19), using another unicellular alga, have mapped the replication origins in Chlamydomonas ctDNA by using EM. One (21) have also used clones SC3-1 and R-13 as templates in a crude in vitro replication system from Chlamydomonas reinhardtii. Both recombinants were found to act as templates.…”

Nucleotide sequence of a preferred maize chloroplast genome template for in vitro DNA synthesis.

“…4A. Eco x has an overall A+T content of region of C. reinhardtii cpDNA (22). This homology accounts 64%, and several regions can be predicted to form stable for the hybridization patterns (Fig.…”

“…The sequence of the nontranscribed strand of ORF 1 is arranged in codons, and the corresponding amino acid sequence is shown below. Translation was started upstream of the first ATG codon (indicated by a double line above the triplet) to maximize homology with the primary structures of the ribosomal protein L16 from tobacco (23), C. reinhardtii (22), and E. coli, which are aligned below the maize gene. Conserved amino acids are boxed.…”

Constitutive Transcription and Stable RNA Accumulation in Plastids during the Conversion of Chloroplasts to Chromoplasts in Ripening Tomato Fruits

“…5). It is interesting that sequences homologous to fragment PstlO were found to contain putative replication origins in maize and Chlamydomonas chloroplasts (4,8,35).…”