Abstract
The locations of the two replication origins in pea chloroplast DNA (ctDNA) have been mapped by electron microscopic analysis of restriction digests of supercoiled ctDNA cross-linked with trioxalen. Both origins of replication, identified as displacement loops (D-loops), were present in the 44-kilobase-pair (kbp) SalI A fragment. The first D-loop was located at 9.0 kbp from the closest SalI restriction site. The average size of this D-loop was about 0.7 kbp. The second D-loop started 14.2 kbp in from the same restriction site and ended at about 15.5 kbp, giving it a size of about 1.3 kbp. The orientation of these two D-loops on the restriction map of pea ctDNA was determined by analyzing SmaI, PstI, and SalI-SmaI restriction digests of pea ctDNA. One D-loop has been mapped in the spacer region between the 16S and 23S rRNA genes. The second D-loop was located downstream of the 23S rRNA gene. Denaturation mapping of recombinants pCP 12-7 and pCB 1-12, which contain both D-loops, confirmed the location of the D-loops in the restriction map of pea ctDNA. Denaturation-mapping studies also showed that the two D-loops had different base compositions; the one closest to a SalI restriction site denatured readily compared with the other D-loop. The recombinants pCP 12-7 and pCB 1-12 were found to be highly active in DNA synthesis when used as templates in a partially purified replication system from pea chloroplasts. Analysis of in vitro-synthesized DNA with either of these recombinants showed that full-length template DNA was synthesized. Recombinants from other regions of the pea chloroplast genome showed no significant DNA synthesis activity in vitro.
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Claims 11
Claim · model-written summary
Both pea chloroplast replication origins were in the 44-kbp SalI A fragment.
- Taxon
- pea
Lathyrus oleraceust0 - Outcome
- origins of replicatione0
- Value
- 44-kilobase-pair (kbp)e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“pea”
e0“Both origins of replication, identified as displacement loops (D-loops), were present in the 44-kilobase-pair (kbp) SalI A fragment.”
Claim · model-written summary
The first D-loop was 9.0 kbp from the closest SalI site.
- Taxon
- peaLathyrus oleraceust0
- Outcome
- first D-loope0
- Value
- 9.0 kbpe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“pea”
e0“The first D-loop was located at 9.0 kbp from the closest SalI restriction site.”
Claim · model-written summary
The first D-loop averaged about 0.7 kbp.
- Taxon
- peaLathyrus oleraceust0
- Outcome
- average size of this D-loope0
- Value
- about 0.7 kbpe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“pea”
e0“The average size of this D-loop was about 0.7 kbp.”
Claim · model-written summary
The second D-loop extended from 14.2 to about 15.5 kbp from the same restriction site.
- Taxon
- peaLathyrus oleraceust0
- Outcome
- second D-loope0
- Value
- 14.2 kbpe0
- Qualifier
- about 15.5 kbpe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“pea”
e0“The second D-loop started 14.2 kbp in from the same restriction site and ended at about 15.5 kbp, giving it a size of about 1.3 kbp.”
Claim · model-written summary
The second D-loop was about 1.3 kbp in size.
- Taxon
- peaLathyrus oleraceust0
- Outcome
- second D-loope0
- Value
- about 1.3 kbpe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“pea”
e0“The second D-loop started 14.2 kbp in from the same restriction site and ended at about 15.5 kbp, giving it a size of about 1.3 kbp.”
Claim · model-written summary
One D-loop mapped between the 16S and 23S rRNA genes.
- Taxon
- peaLathyrus oleraceust0
- Gene
- 16S and 23S rRNA genese0
- Outcome
- D-loope0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“pea”
e0“One D-loop has been mapped in the spacer region between the 16S and 23S rRNA genes.”
Claim · model-written summary
The second D-loop mapped downstream of the 23S rRNA gene.
- Taxon
- peaLathyrus oleraceust0
- Gene
- 23S rRNA genee0
- Outcome
- second D-loope0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“pea”
e0“The second D-loop was located downstream of the 23S rRNA gene.”
Claim · model-written summary
The D-loops differed in base composition, with the one nearest a SalI site denaturing more readily.
- Taxon
- peaLathyrus oleraceust0
- Outcome
- different base compositionse0
- Comparator
- the other D-loope0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“pea”
e0“the two D-loops had different base compositions; the one closest to a SalI restriction site denatured readily compared with the other D-loop”
Claim · model-written summary
Recombinants pCP 12-7 and pCB 1-12 were highly active in DNA synthesis as templates.
- Taxon
- peaLathyrus oleraceuse0
- Material
- pCP 12-7 and pCB 1-12e0
- Outcome
- DNA synthesise0
- Direction
- highly activee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“pea”
e0“The recombinants pCP 12-7 and pCB 1-12 were found to be highly active in DNA synthesis when used as templates in a partially purified replication system from pea chloroplasts.”
Claim · model-written summary
Either D-loop recombinant supported full-length template DNA synthesis.
- Taxon
- peaLathyrus oleraceust0
- Outcome
- full-length template DNA was synthesizede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“pea”
e0“Analysis of in vitro-synthesized DNA with either of these recombinants showed that full-length template DNA was synthesized.”
Claim · model-written summary
Recombinants from other pea chloroplast regions showed no significant in vitro DNA synthesis.
- Taxon
- peaLathyrus oleraceuse0
- Outcome
- DNA synthesis activitye0
- Direction
- no significante0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Recombinants from other regions of the pea chloroplast genome showed no significant DNA synthesis activity in vitro.”